{
    "document": {
        "category": "csaf_base",
        "csaf_version": "2.0",
        "distribution": {
            "tlp": {
                "label": "WHITE"
            }
        },
        "lang": "en",
        "notes": [
            {
                "category": "legal_disclaimer",
                "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings."
            }
        ],
        "publisher": {
            "category": "coordinator",
            "contact_details": "cert@ncsc.nl",
            "name": "National Cyber Security Centre",
            "namespace": "https://www.ncsc.nl/"
        },
        "title": "CVE-2026-23406",
        "tracking": {
            "current_release_date": "2026-04-02T16:20:23.132622Z",
            "generator": {
                "date": "2026-02-17T15:00:00Z",
                "engine": {
                    "name": "V.E.L.M.A",
                    "version": "1.7"
                }
            },
            "id": "CVE-2026-23406",
            "initial_release_date": "2026-04-01T09:25:18.928263Z",
            "revision_history": [
                {
                    "date": "2026-04-01T09:25:18.928263Z",
                    "number": "1",
                    "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| References created (5)."
                },
                {
                    "date": "2026-04-01T09:25:31.360107Z",
                    "number": "2",
                    "summary": "NCSC Score created."
                },
                {
                    "date": "2026-04-01T09:38:47.079694Z",
                    "number": "3",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| Products created (5).| Products connected (7).| References created (5)."
                },
                {
                    "date": "2026-04-01T09:38:50.719850Z",
                    "number": "4",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-04-01T11:36:27.701780Z",
                    "number": "5",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-04-01T12:06:07.563772Z",
                    "number": "6",
                    "summary": "Source connected.| CVE status created. (valid)| Products connected (1).| References created (14)."
                },
                {
                    "date": "2026-04-01T12:06:16.615963Z",
                    "number": "7",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-04-01T15:37:43.595058Z",
                    "number": "8",
                    "summary": "Source connected.| CVE status created. (valid)| EPSS created."
                },
                {
                    "date": "2026-04-01T15:37:45.931057Z",
                    "number": "9",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-04-01T18:43:46.270562Z",
                    "number": "10",
                    "summary": "Source created.| CVE status created. (valid)| Products connected (2).| Product Identifiers created (2)."
                },
                {
                    "date": "2026-04-02T00:27:44.850847Z",
                    "number": "11",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| Products connected (13).| Product Identifiers created (5).| References created (3).| CWES updated (1)."
                },
                {
                    "date": "2026-04-02T06:44:43.893865Z",
                    "number": "12",
                    "summary": "Description created for source."
                },
                {
                    "date": "2026-04-02T08:05:49.820323Z",
                    "number": "13",
                    "summary": "Products connected (1).| References created (1)."
                },
                {
                    "date": "2026-04-02T15:28:10.927461Z",
                    "number": "14",
                    "summary": "CVSS created."
                },
                {
                    "date": "2026-04-02T15:28:12.947972Z",
                    "number": "15",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-04-02T15:39:53.242924Z",
                    "number": "16",
                    "summary": "CVSS created."
                },
                {
                    "date": "2026-04-02T15:39:58.037765Z",
                    "number": "17",
                    "summary": "NCSC Score updated."
                }
            ],
            "status": "interim",
            "version": "17"
        }
    },
    "product_tree": {
        "branches": [
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:git/074c1cd798cb0b481d7eaa749b64aa416563c053|<0510d1ba0976f97f521feb2b75b0572ea5df3ceb",
                                "product": {
                                    "name": "vers:git/074c1cd798cb0b481d7eaa749b64aa416563c053|<0510d1ba0976f97f521feb2b75b0572ea5df3ceb",
                                    "product_id": "CSAFPID-5971783"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:git/074c1cd798cb0b481d7eaa749b64aa416563c053|<383b7270faf42564f133134c2fc3c24bbae52615",
                                "product": {
                                    "name": "vers:git/074c1cd798cb0b481d7eaa749b64aa416563c053|<383b7270faf42564f133134c2fc3c24bbae52615",
                                    "product_id": "CSAFPID-5971784"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:git/074c1cd798cb0b481d7eaa749b64aa416563c053|<5a184f7cbdeaad17e16dedf3c17d0cd622edfed8",
                                "product": {
                                    "name": "vers:git/074c1cd798cb0b481d7eaa749b64aa416563c053|<5a184f7cbdeaad17e16dedf3c17d0cd622edfed8",
                                    "product_id": "CSAFPID-5971781"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:git/074c1cd798cb0b481d7eaa749b64aa416563c053|<8756b68edae37ff546c02091989a4ceab3f20abd",
                                "product": {
                                    "name": "vers:git/074c1cd798cb0b481d7eaa749b64aa416563c053|<8756b68edae37ff546c02091989a4ceab3f20abd",
                                    "product_id": "CSAFPID-5971785"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:git/074c1cd798cb0b481d7eaa749b64aa416563c053|<b73c1dff8a9d7eeaebabf8097a5b2de192f40913",
                                "product": {
                                    "name": "vers:git/074c1cd798cb0b481d7eaa749b64aa416563c053|<b73c1dff8a9d7eeaebabf8097a5b2de192f40913",
                                    "product_id": "CSAFPID-5971782"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:semver/6.12.77|<=6.12.*",
                                "product": {
                                    "name": "vers:semver/6.12.77|<=6.12.*",
                                    "product_id": "CSAFPID-5815258"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:semver/6.18.18|<=6.18.*",
                                "product": {
                                    "name": "vers:semver/6.18.18|<=6.18.*",
                                    "product_id": "CSAFPID-5843471"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:semver/6.19.8|<=6.19.*",
                                "product": {
                                    "name": "vers:semver/6.19.8|<=6.19.*",
                                    "product_id": "CSAFPID-5843472"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:semver/6.6.130|<=6.6.*",
                                "product": {
                                    "name": "vers:semver/6.6.130|<=6.6.*",
                                    "product_id": "CSAFPID-5904647"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:semver/<4.17",
                                "product": {
                                    "name": "vers:semver/<4.17",
                                    "product_id": "CSAFPID-1286709"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/4.17",
                                "product": {
                                    "name": "vers:unknown/4.17",
                                    "product_id": "CSAFPID-1286708"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/7.0-rc4|<=*",
                                "product": {
                                    "name": "vers:unknown/7.0-rc4|<=*",
                                    "product_id": "CSAFPID-5844856"
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "Linux"
                    }
                ],
                "category": "vendor",
                "name": "Linux"
            },
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/unknown",
                                "product": {
                                    "name": "vers:unknown/unknown",
                                    "product_id": "CSAFPID-1330297",
                                    "product_identification_helper": {
                                        "cpe": "cpe:/o:open_source:linux:-"
                                    }
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "Open Source Linux Kernel"
                    }
                ],
                "category": "vendor",
                "name": "Open Source"
            },
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/unknown",
                                "product": {
                                    "name": "vers:unknown/unknown",
                                    "product_id": "CSAFPID-1317177",
                                    "product_identification_helper": {
                                        "cpe": "cpe:/o:oracle:linux:-"
                                    }
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "Oracle Linux"
                    }
                ],
                "category": "vendor",
                "name": "Oracle"
            },
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:rpm/10",
                                "product": {
                                    "name": "vers:rpm/10",
                                    "product_id": "CSAFPID-2858634",
                                    "product_identification_helper": {
                                        "cpe": "cpe:/o:redhat:enterprise_linux:10"
                                    }
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "Red Hat Enterprise Linux 10"
                    },
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:rpm/6",
                                "product": {
                                    "name": "vers:rpm/6",
                                    "product_id": "CSAFPID-1439321",
                                    "product_identification_helper": {
                                        "cpe": "cpe:/o:redhat:enterprise_linux:6"
                                    }
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "Red Hat Enterprise Linux 6"
                    },
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:rpm/7",
                                "product": {
                                    "name": "vers:rpm/7",
                                    "product_id": "CSAFPID-1439315",
                                    "product_identification_helper": {
                                        "cpe": "cpe:/o:redhat:enterprise_linux:7"
                                    }
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "Red Hat Enterprise Linux 7"
                    },
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:rpm/8",
                                "product": {
                                    "name": "vers:rpm/8",
                                    "product_id": "CSAFPID-1439317",
                                    "product_identification_helper": {
                                        "cpe": "cpe:/o:redhat:enterprise_linux:8"
                                    }
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "Red Hat Enterprise Linux 8"
                    },
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:rpm/9",
                                "product": {
                                    "name": "vers:rpm/9",
                                    "product_id": "CSAFPID-1439319",
                                    "product_identification_helper": {
                                        "cpe": "cpe:/a:redhat:enterprise_linux:9"
                                    }
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "Red Hat Enterprise Linux 9"
                    },
                    {
                        "branches": [
                            {
                                "branches": [
                                    {
                                        "category": "product_version_range",
                                        "name": "vers:rpm/unknown",
                                        "product": {
                                            "name": "vers:rpm/unknown",
                                            "product_id": "CSAFPID-2858635"
                                        }
                                    }
                                ],
                                "category": "product_name",
                                "name": "kernel"
                            }
                        ],
                        "category": "product_family",
                        "name": "Red Hat Enterprise Linux 10"
                    },
                    {
                        "branches": [
                            {
                                "branches": [
                                    {
                                        "category": "product_version_range",
                                        "name": "vers:rpm/unknown",
                                        "product": {
                                            "name": "vers:rpm/unknown",
                                            "product_id": "CSAFPID-1453376"
                                        }
                                    }
                                ],
                                "category": "product_name",
                                "name": "kernel"
                            }
                        ],
                        "category": "product_family",
                        "name": "Red Hat Enterprise Linux 6"
                    },
                    {
                        "branches": [
                            {
                                "branches": [
                                    {
                                        "category": "product_version_range",
                                        "name": "vers:rpm/unknown",
                                        "product": {
                                            "name": "vers:rpm/unknown",
                                            "product_id": "CSAFPID-1453377"
                                        }
                                    }
                                ],
                                "category": "product_name",
                                "name": "kernel"
                            },
                            {
                                "branches": [
                                    {
                                        "category": "product_version_range",
                                        "name": "vers:rpm/unknown",
                                        "product": {
                                            "name": "vers:rpm/unknown",
                                            "product_id": "CSAFPID-1453378"
                                        }
                                    }
                                ],
                                "category": "product_name",
                                "name": "kernel-rt"
                            }
                        ],
                        "category": "product_family",
                        "name": "Red Hat Enterprise Linux 7"
                    },
                    {
                        "branches": [
                            {
                                "branches": [
                                    {
                                        "category": "product_version_range",
                                        "name": "vers:rpm/unknown",
                                        "product": {
                                            "name": "vers:rpm/unknown",
                                            "product_id": "CSAFPID-1453379"
                                        }
                                    }
                                ],
                                "category": "product_name",
                                "name": "kernel"
                            },
                            {
                                "branches": [
                                    {
                                        "category": "product_version_range",
                                        "name": "vers:rpm/unknown",
                                        "product": {
                                            "name": "vers:rpm/unknown",
                                            "product_id": "CSAFPID-1453380"
                                        }
                                    }
                                ],
                                "category": "product_name",
                                "name": "kernel-rt"
                            }
                        ],
                        "category": "product_family",
                        "name": "Red Hat Enterprise Linux 8"
                    },
                    {
                        "branches": [
                            {
                                "branches": [
                                    {
                                        "category": "product_version_range",
                                        "name": "vers:rpm/unknown",
                                        "product": {
                                            "name": "vers:rpm/unknown",
                                            "product_id": "CSAFPID-1453381"
                                        }
                                    }
                                ],
                                "category": "product_name",
                                "name": "kernel"
                            },
                            {
                                "branches": [
                                    {
                                        "category": "product_version_range",
                                        "name": "vers:rpm/unknown",
                                        "product": {
                                            "name": "vers:rpm/unknown",
                                            "product_id": "CSAFPID-1453382"
                                        }
                                    }
                                ],
                                "category": "product_name",
                                "name": "kernel-rt"
                            }
                        ],
                        "category": "product_family",
                        "name": "Red Hat Enterprise Linux 9"
                    }
                ],
                "category": "vendor",
                "name": "Red Hat"
            },
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "branches": [
                                    {
                                        "category": "product_version_range",
                                        "name": "vers:deb/6.1.164-1",
                                        "product": {
                                            "name": "vers:deb/6.1.164-1",
                                            "product_id": "CSAFPID-5812295",
                                            "product_identification_helper": {
                                                "purl": "pkg:deb/debian/linux@6.1.164-1?distro=bookworm"
                                            }
                                        }
                                    }
                                ],
                                "category": "product_name",
                                "name": "linux"
                            }
                        ],
                        "category": "product_family",
                        "name": "bookworm"
                    },
                    {
                        "branches": [
                            {
                                "branches": [
                                    {
                                        "category": "product_version_range",
                                        "name": "vers:deb/5.10.251-1",
                                        "product": {
                                            "name": "vers:deb/5.10.251-1",
                                            "product_id": "CSAFPID-5815374",
                                            "product_identification_helper": {
                                                "purl": "pkg:deb/debian/linux@5.10.251-1?distro=bullseye"
                                            }
                                        }
                                    }
                                ],
                                "category": "product_name",
                                "name": "linux"
                            }
                        ],
                        "category": "product_family",
                        "name": "bullseye"
                    }
                ],
                "category": "vendor",
                "name": "Debian"
            }
        ]
    },
    "vulnerabilities": [
        {
            "cve": "CVE-2026-23406",
            "notes": [
                {
                    "category": "description",
                    "text": "In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: fix side-effect bug in match_char() macro usage\n\nThe match_char() macro evaluates its character parameter multiple\ntimes when traversing differential encoding chains. When invoked\nwith *str++, the string pointer advances on each iteration of the\ninner do-while loop, causing the DFA to check different characters\nat each iteration and therefore skip input characters.\nThis results in out-of-bounds reads when the pointer advances past\nthe input buffer boundary.\n\n[   94.984676] ==================================================================\n[   94.985301] BUG: KASAN: slab-out-of-bounds in aa_dfa_match+0x5ae/0x760\n[   94.985655] Read of size 1 at addr ffff888100342000 by task file/976\n\n[   94.986319] CPU: 7 UID: 1000 PID: 976 Comm: file Not tainted 6.19.0-rc7-next-20260127 #1 PREEMPT(lazy)\n[   94.986322] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n[   94.986329] Call Trace:\n[   94.986341]  <TASK>\n[   94.986347]  dump_stack_lvl+0x5e/0x80\n[   94.986374]  print_report+0xc8/0x270\n[   94.986384]  ? aa_dfa_match+0x5ae/0x760\n[   94.986388]  kasan_report+0x118/0x150\n[   94.986401]  ? aa_dfa_match+0x5ae/0x760\n[   94.986405]  aa_dfa_match+0x5ae/0x760\n[   94.986408]  __aa_path_perm+0x131/0x400\n[   94.986418]  aa_path_perm+0x219/0x2f0\n[   94.986424]  apparmor_file_open+0x345/0x570\n[   94.986431]  security_file_open+0x5c/0x140\n[   94.986442]  do_dentry_open+0x2f6/0x1120\n[   94.986450]  vfs_open+0x38/0x2b0\n[   94.986453]  ? may_open+0x1e2/0x2b0\n[   94.986466]  path_openat+0x231b/0x2b30\n[   94.986469]  ? __x64_sys_openat+0xf8/0x130\n[   94.986477]  do_file_open+0x19d/0x360\n[   94.986487]  do_sys_openat2+0x98/0x100\n[   94.986491]  __x64_sys_openat+0xf8/0x130\n[   94.986499]  do_syscall_64+0x8e/0x660\n[   94.986515]  ? count_memcg_events+0x15f/0x3c0\n[   94.986526]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   94.986540]  ? handle_mm_fault+0x1639/0x1ef0\n[   94.986551]  ? vma_start_read+0xf0/0x320\n[   94.986558]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   94.986561]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   94.986563]  ? fpregs_assert_state_consistent+0x50/0xe0\n[   94.986572]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   94.986574]  ? arch_exit_to_user_mode_prepare+0x9/0xb0\n[   94.986587]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   94.986588]  ? irqentry_exit+0x3c/0x590\n[   94.986595]  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n[   94.986597] RIP: 0033:0x7fda4a79c3ea\n\nFix by extracting the character value before invoking match_char,\nensuring single evaluation per outer loop.",
                    "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-23406"
                },
                {
                    "category": "description",
                    "text": "In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: fix side-effect bug in match_char() macro usage\n\nThe match_char() macro evaluates its character parameter multiple\ntimes when traversing differential encoding chains. When invoked\nwith *str++, the string pointer advances on each iteration of the\ninner do-while loop, causing the DFA to check different characters\nat each iteration and therefore skip input characters.\nThis results in out-of-bounds reads when the pointer advances past\nthe input buffer boundary.\n\n[   94.984676] ==================================================================\n[   94.985301] BUG: KASAN: slab-out-of-bounds in aa_dfa_match+0x5ae/0x760\n[   94.985655] Read of size 1 at addr ffff888100342000 by task file/976\n\n[   94.986319] CPU: 7 UID: 1000 PID: 976 Comm: file Not tainted 6.19.0-rc7-next-20260127 #1 PREEMPT(lazy)\n[   94.986322] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n[   94.986329] Call Trace:\n[   94.986341]  <TASK>\n[   94.986347]  dump_stack_lvl+0x5e/0x80\n[   94.986374]  print_report+0xc8/0x270\n[   94.986384]  ? aa_dfa_match+0x5ae/0x760\n[   94.986388]  kasan_report+0x118/0x150\n[   94.986401]  ? aa_dfa_match+0x5ae/0x760\n[   94.986405]  aa_dfa_match+0x5ae/0x760\n[   94.986408]  __aa_path_perm+0x131/0x400\n[   94.986418]  aa_path_perm+0x219/0x2f0\n[   94.986424]  apparmor_file_open+0x345/0x570\n[   94.986431]  security_file_open+0x5c/0x140\n[   94.986442]  do_dentry_open+0x2f6/0x1120\n[   94.986450]  vfs_open+0x38/0x2b0\n[   94.986453]  ? may_open+0x1e2/0x2b0\n[   94.986466]  path_openat+0x231b/0x2b30\n[   94.986469]  ? __x64_sys_openat+0xf8/0x130\n[   94.986477]  do_file_open+0x19d/0x360\n[   94.986487]  do_sys_openat2+0x98/0x100\n[   94.986491]  __x64_sys_openat+0xf8/0x130\n[   94.986499]  do_syscall_64+0x8e/0x660\n[   94.986515]  ? count_memcg_events+0x15f/0x3c0\n[   94.986526]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   94.986540]  ? handle_mm_fault+0x1639/0x1ef0\n[   94.986551]  ? vma_start_read+0xf0/0x320\n[   94.986558]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   94.986561]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   94.986563]  ? fpregs_assert_state_consistent+0x50/0xe0\n[   94.986572]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   94.986574]  ? arch_exit_to_user_mode_prepare+0x9/0xb0\n[   94.986587]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   94.986588]  ? irqentry_exit+0x3c/0x590\n[   94.986595]  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n[   94.986597] RIP: 0033:0x7fda4a79c3ea\n\nFix by extracting the character value before invoking match_char,\nensuring single evaluation per outer loop.",
                    "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/23xxx/CVE-2026-23406.json"
                },
                {
                    "category": "description",
                    "text": "A flaw was found in AppArmor within the Linux kernel. The `match_char()` macro, when processing differential encoding chains, incorrectly advances the string pointer multiple times. This can lead to an out-of-bounds read when the pointer moves beyond the input buffer boundary. A local attacker could exploit this memory corruption vulnerability, potentially causing a denial of service or information disclosure.",
                    "title": "redhat - https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-23406.json"
                },
                {
                    "category": "description",
                    "text": "In the Linux kernel, the following vulnerability has been resolved:  apparmor: fix side-effect bug in match_char() macro usage  The match_char() macro evaluates its character parameter multiple times when traversing differential encoding chains. When invoked with *str++, the string pointer advances on each iteration of the inner do-while loop, causing the DFA to check different characters at each iteration and therefore skip input characters. This results in out-of-bounds reads when the pointer advances past the input buffer boundary.  [   94.984676] ================================================================== [   94.985301] BUG: KASAN: slab-out-of-bounds in aa_dfa_match+0x5ae/0x760 [   94.985655] Read of size 1 at addr ffff888100342000 by task file/976  [   94.986319] CPU: 7 UID: 1000 PID: 976 Comm: file Not tainted 6.19.0-rc7-next-20260127 #1 PREEMPT(lazy) [   94.986322] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [   94.986329] Call Trace: [   94.986341]  <TASK> [   94.986347]  dump_stack_lvl+0x5e/0x80 [   94.986374]  print_report+0xc8/0x270 [   94.986384]  ? aa_dfa_match+0x5ae/0x760 [   94.986388]  kasan_report+0x118/0x150 [   94.986401]  ? aa_dfa_match+0x5ae/0x760 [   94.986405]  aa_dfa_match+0x5ae/0x760 [   94.986408]  __aa_path_perm+0x131/0x400 [   94.986418]  aa_path_perm+0x219/0x2f0 [   94.986424]  apparmor_file_open+0x345/0x570 [   94.986431]  security_file_open+0x5c/0x140 [   94.986442]  do_dentry_open+0x2f6/0x1120 [   94.986450]  vfs_open+0x38/0x2b0 [   94.986453]  ? may_open+0x1e2/0x2b0 [   94.986466]  path_openat+0x231b/0x2b30 [   94.986469]  ? __x64_sys_openat+0xf8/0x130 [   94.986477]  do_file_open+0x19d/0x360 [   94.986487]  do_sys_openat2+0x98/0x100 [   94.986491]  __x64_sys_openat+0xf8/0x130 [   94.986499]  do_syscall_64+0x8e/0x660 [   94.986515]  ? count_memcg_events+0x15f/0x3c0 [   94.986526]  ? srso_alias_return_thunk+0x5/0xfbef5 [   94.986540]  ? handle_mm_fault+0x1639/0x1ef0 [   94.986551]  ? vma_start_read+0xf0/0x320 [   94.986558]  ? srso_alias_return_thunk+0x5/0xfbef5 [   94.986561]  ? srso_alias_return_thunk+0x5/0xfbef5 [   94.986563]  ? fpregs_assert_state_consistent+0x50/0xe0 [   94.986572]  ? srso_alias_return_thunk+0x5/0xfbef5 [   94.986574]  ? arch_exit_to_user_mode_prepare+0x9/0xb0 [   94.986587]  ? srso_alias_return_thunk+0x5/0xfbef5 [   94.986588]  ? irqentry_exit+0x3c/0x590 [   94.986595]  entry_SYSCALL_64_after_hwframe+0x76/0x7e [   94.986597] RIP: 0033:0x7fda4a79c3ea  Fix by extracting the character value before invoking match_char, ensuring single evaluation per outer loop.",
                    "title": "debian - https://security-tracker.debian.org/tracker/CVE-2026-23406"
                },
                {
                    "category": "other",
                    "text": "0.00018",
                    "title": "EPSS"
                },
                {
                    "category": "other",
                    "text": "4.2",
                    "title": "NCSC Score"
                },
                {
                    "category": "other",
                    "text": "There is product data available from source Certbundde",
                    "title": "NCSC Score top increasing factors"
                },
                {
                    "category": "other",
                    "text": "The value of the most recent EPSS score, Is related to a product by vendor Linux",
                    "title": "NCSC Score top decreasing factors"
                }
            ],
            "product_status": {
                "first_fixed": [
                    "CSAFPID-5812295",
                    "CSAFPID-5815374"
                ],
                "known_affected": [
                    "CSAFPID-1286708",
                    "CSAFPID-5971781",
                    "CSAFPID-5971782",
                    "CSAFPID-5971783",
                    "CSAFPID-5971784",
                    "CSAFPID-5971785",
                    "CSAFPID-1330297",
                    "CSAFPID-1317177"
                ],
                "known_not_affected": [
                    "CSAFPID-1286709",
                    "CSAFPID-5815258",
                    "CSAFPID-5843471",
                    "CSAFPID-5843472",
                    "CSAFPID-5844856",
                    "CSAFPID-5904647",
                    "CSAFPID-1439315",
                    "CSAFPID-1439317",
                    "CSAFPID-1439319",
                    "CSAFPID-1439321",
                    "CSAFPID-1453376",
                    "CSAFPID-1453377",
                    "CSAFPID-1453378",
                    "CSAFPID-1453379",
                    "CSAFPID-1453380",
                    "CSAFPID-1453381",
                    "CSAFPID-1453382",
                    "CSAFPID-2858634",
                    "CSAFPID-2858635"
                ]
            },
            "references": [
                {
                    "category": "external",
                    "summary": "Source - nvd",
                    "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-23406"
                },
                {
                    "category": "external",
                    "summary": "Source - cveprojectv5",
                    "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/23xxx/CVE-2026-23406.json"
                },
                {
                    "category": "external",
                    "summary": "Source - certbundde",
                    "url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-0950.json"
                },
                {
                    "category": "external",
                    "summary": "Source - first",
                    "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
                },
                {
                    "category": "external",
                    "summary": "Source - debian",
                    "url": "https://security-tracker.debian.org/tracker/CVE-2026-23406"
                },
                {
                    "category": "external",
                    "summary": "Source - redhat",
                    "url": "https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-23406.json"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://git.kernel.org/stable/c/0510d1ba0976f97f521feb2b75b0572ea5df3ceb"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://git.kernel.org/stable/c/383b7270faf42564f133134c2fc3c24bbae52615"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://git.kernel.org/stable/c/5a184f7cbdeaad17e16dedf3c17d0cd622edfed8"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://git.kernel.org/stable/c/8756b68edae37ff546c02091989a4ceab3f20abd"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://git.kernel.org/stable/c/b73c1dff8a9d7eeaebabf8097a5b2de192f40913"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-0950.json"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-0950"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://lore.kernel.org/linux-cve-announce/"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://lore.kernel.org/linux-cve-announce/2026040108-CVE-2026-23401-956d@gregkh/"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://lore.kernel.org/linux-cve-announce/2026040110-CVE-2026-23402-c852@gregkh/"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://lore.kernel.org/linux-cve-announce/2026040111-CVE-2026-23403-f22c@gregkh/"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://lore.kernel.org/linux-cve-announce/2026040111-CVE-2026-23404-8b0b@gregkh/"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://lore.kernel.org/linux-cve-announce/2026040111-CVE-2026-23405-0e7a@gregkh/"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://lore.kernel.org/linux-cve-announce/2026040112-CVE-2026-23406-0cb2@gregkh/"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://lore.kernel.org/linux-cve-announce/2026040112-CVE-2026-23407-297e@gregkh/"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://lore.kernel.org/linux-cve-announce/2026040113-CVE-2026-23408-1932@gregkh/"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://lore.kernel.org/linux-cve-announce/2026040113-CVE-2026-23409-ae18@gregkh/"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://lore.kernel.org/linux-cve-announce/2026040113-CVE-2026-23410-d7d5@gregkh/"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://lore.kernel.org/linux-cve-announce/2026040114-CVE-2026-23411-00f7@gregkh/"
                },
                {
                    "category": "external",
                    "summary": "Reference - redhat",
                    "url": "https://www.cve.org/CVERecord?id=CVE-2026-23406"
                },
                {
                    "category": "external",
                    "summary": "Reference - redhat",
                    "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23406"
                },
                {
                    "category": "external",
                    "summary": "Reference - redhat",
                    "url": "https://lore.kernel.org/linux-cve-announce/2026040112-CVE-2026-23406-0cb2@gregkh/T"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://linux.oracle.com/errata/ELSA-2026-50170.html"
                }
            ],
            "scores": [
                {
                    "cvss_v3": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 7.8,
                        "baseSeverity": "HIGH"
                    },
                    "products": [
                        "CSAFPID-1286708",
                        "CSAFPID-1317177",
                        "CSAFPID-1330297",
                        "CSAFPID-5971781",
                        "CSAFPID-5971782",
                        "CSAFPID-5971783",
                        "CSAFPID-5971784",
                        "CSAFPID-5971785"
                    ]
                }
            ],
            "title": "CVE-2026-23406"
        }
    ]
}