{
    "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-2026-31392",
        "tracking": {
            "current_release_date": "2026-04-03T16:50:13.524972Z",
            "generator": {
                "date": "2026-02-17T15:00:00Z",
                "engine": {
                    "name": "V.E.L.M.A",
                    "version": "1.7"
                }
            },
            "id": "CVE-2026-31392",
            "initial_release_date": "2026-04-03T15:39:21.897405Z",
            "revision_history": [
                {
                    "date": "2026-04-03T15:39:21.897405Z",
                    "number": "1",
                    "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| Products created (6).| Products connected (6).| References created (6)."
                },
                {
                    "date": "2026-04-03T15:39:28.827232Z",
                    "number": "2",
                    "summary": "NCSC Score created."
                },
                {
                    "date": "2026-04-03T16:50:12.267518Z",
                    "number": "3",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| References created (6)."
                }
            ],
            "status": "interim",
            "version": "3"
        }
    },
    "product_tree": {
        "branches": [
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:git/1da177e4c3f41524e886b7f1b8a0c1fc7321cac2|<12b4c5d98cd7ca46d5035a57bcd995df614c14e1",
                                "product": {
                                    "name": "vers:git/1da177e4c3f41524e886b7f1b8a0c1fc7321cac2|<12b4c5d98cd7ca46d5035a57bcd995df614c14e1",
                                    "product_id": "CSAFPID-5992219"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:git/1da177e4c3f41524e886b7f1b8a0c1fc7321cac2|<6e9ff1eb7feedcf46ff2d0503759960ab58e7775",
                                "product": {
                                    "name": "vers:git/1da177e4c3f41524e886b7f1b8a0c1fc7321cac2|<6e9ff1eb7feedcf46ff2d0503759960ab58e7775",
                                    "product_id": "CSAFPID-5992218"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:git/1da177e4c3f41524e886b7f1b8a0c1fc7321cac2|<9229709ec8bf85ae7ca53aeee9aa14814cdc1bd2",
                                "product": {
                                    "name": "vers:git/1da177e4c3f41524e886b7f1b8a0c1fc7321cac2|<9229709ec8bf85ae7ca53aeee9aa14814cdc1bd2",
                                    "product_id": "CSAFPID-5992215"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:git/1da177e4c3f41524e886b7f1b8a0c1fc7321cac2|<9ee803bfdba0cf739038dbdabdd4c02582c8f2b2",
                                "product": {
                                    "name": "vers:git/1da177e4c3f41524e886b7f1b8a0c1fc7321cac2|<9ee803bfdba0cf739038dbdabdd4c02582c8f2b2",
                                    "product_id": "CSAFPID-5992217"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:git/1da177e4c3f41524e886b7f1b8a0c1fc7321cac2|<d33cbf0bf8979d779900da9be2505d68d9d8da25",
                                "product": {
                                    "name": "vers:git/1da177e4c3f41524e886b7f1b8a0c1fc7321cac2|<d33cbf0bf8979d779900da9be2505d68d9d8da25",
                                    "product_id": "CSAFPID-5992216"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:git/1da177e4c3f41524e886b7f1b8a0c1fc7321cac2|<fd4547830720647d4af02ee50f883c4b1cca06e4",
                                "product": {
                                    "name": "vers:git/1da177e4c3f41524e886b7f1b8a0c1fc7321cac2|<fd4547830720647d4af02ee50f883c4b1cca06e4",
                                    "product_id": "CSAFPID-5992214"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:semver/6.1.167|<=6.1.*",
                                "product": {
                                    "name": "vers:semver/6.1.167|<=6.1.*",
                                    "product_id": "CSAFPID-5904654"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:semver/6.12.78|<=6.12.*",
                                "product": {
                                    "name": "vers:semver/6.12.78|<=6.12.*",
                                    "product_id": "CSAFPID-5904671"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:semver/6.18.20|<=6.18.*",
                                "product": {
                                    "name": "vers:semver/6.18.20|<=6.18.*",
                                    "product_id": "CSAFPID-5905005"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:semver/6.19.10|<=6.19.*",
                                "product": {
                                    "name": "vers:semver/6.19.10|<=6.19.*",
                                    "product_id": "CSAFPID-5905006"
                                }
                            },
                            {
                                "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:unknown/7.0-rc5|<=*",
                                "product": {
                                    "name": "vers:unknown/7.0-rc5|<=*",
                                    "product_id": "CSAFPID-5905027"
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "Linux"
                    }
                ],
                "category": "vendor",
                "name": "Linux"
            }
        ]
    },
    "vulnerabilities": [
        {
            "cve": "CVE-2026-31392",
            "notes": [
                {
                    "category": "description",
                    "text": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix krb5 mount with username option\n\nCustomer reported that some of their krb5 mounts were failing against\na single server as the client was trying to mount the shares with\nwrong credentials.  It turned out the client was reusing SMB session\nfrom first mount to try mounting the other shares, even though a\ndifferent username= option had been specified to the other mounts.\n\nBy using username mount option along with sec=krb5 to search for\nprincipals from keytab is supported by cifs.upcall(8) since\ncifs-utils-4.8.  So fix this by matching username mount option in\nmatch_session() even with Kerberos.\n\nFor example, the second mount below should fail with -ENOKEY as there\nis no 'foobar' principal in keytab (/etc/krb5.keytab).  The client\nends up reusing SMB session from first mount to perform the second\none, which is wrong.\n\n```\n$ ktutil\nktutil:  add_entry -password -p testuser -k 1 -e aes256-cts\nPassword for testuser@ZELDA.TEST:\nktutil:  write_kt /etc/krb5.keytab\nktutil:  quit\n$ klist -ke\nKeytab name: FILE:/etc/krb5.keytab\nKVNO Principal\n ---- ----------------------------------------------------------------\n   1 testuser@ZELDA.TEST (aes256-cts-hmac-sha1-96)\n$ mount.cifs //w22-root2/scratch /mnt/1 -o sec=krb5,username=testuser\n$ mount.cifs //w22-root2/scratch /mnt/2 -o sec=krb5,username=foobar\n$ mount -t cifs | grep -Po 'username=\\K\\w+'\ntestuser\ntestuser\n```",
                    "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/31xxx/CVE-2026-31392.json"
                },
                {
                    "category": "description",
                    "text": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix krb5 mount with username option\n\nCustomer reported that some of their krb5 mounts were failing against\na single server as the client was trying to mount the shares with\nwrong credentials.  It turned out the client was reusing SMB session\nfrom first mount to try mounting the other shares, even though a\ndifferent username= option had been specified to the other mounts.\n\nBy using username mount option along with sec=krb5 to search for\nprincipals from keytab is supported by cifs.upcall(8) since\ncifs-utils-4.8.  So fix this by matching username mount option in\nmatch_session() even with Kerberos.\n\nFor example, the second mount below should fail with -ENOKEY as there\nis no 'foobar' principal in keytab (/etc/krb5.keytab).  The client\nends up reusing SMB session from first mount to perform the second\none, which is wrong.\n\n```\n$ ktutil\nktutil:  add_entry -password -p testuser -k 1 -e aes256-cts\nPassword for testuser@ZELDA.TEST:\nktutil:  write_kt /etc/krb5.keytab\nktutil:  quit\n$ klist -ke\nKeytab name: FILE:/etc/krb5.keytab\nKVNO Principal\n ---- ----------------------------------------------------------------\n   1 testuser@ZELDA.TEST (aes256-cts-hmac-sha1-96)\n$ mount.cifs //w22-root2/scratch /mnt/1 -o sec=krb5,username=testuser\n$ mount.cifs //w22-root2/scratch /mnt/2 -o sec=krb5,username=foobar\n$ mount -t cifs | grep -Po 'username=\\K\\w+'\ntestuser\ntestuser\n```",
                    "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-31392"
                },
                {
                    "category": "other",
                    "text": "4.1",
                    "title": "NCSC Score"
                },
                {
                    "category": "other",
                    "text": "The value of the most recent CVSS (V3) score, Is related to a product by vendor Linux",
                    "title": "NCSC Score top decreasing factors"
                }
            ],
            "product_status": {
                "known_affected": [
                    "CSAFPID-5992214",
                    "CSAFPID-5992215",
                    "CSAFPID-5992216",
                    "CSAFPID-5992217",
                    "CSAFPID-5992218",
                    "CSAFPID-5992219"
                ],
                "known_not_affected": [
                    "CSAFPID-5904647",
                    "CSAFPID-5904654",
                    "CSAFPID-5904671",
                    "CSAFPID-5905005",
                    "CSAFPID-5905006",
                    "CSAFPID-5905027"
                ]
            },
            "references": [
                {
                    "category": "external",
                    "summary": "Source - cveprojectv5",
                    "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/31xxx/CVE-2026-31392.json"
                },
                {
                    "category": "external",
                    "summary": "Source - nvd",
                    "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-31392"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://git.kernel.org/stable/c/fd4547830720647d4af02ee50f883c4b1cca06e4"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://git.kernel.org/stable/c/9229709ec8bf85ae7ca53aeee9aa14814cdc1bd2"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://git.kernel.org/stable/c/d33cbf0bf8979d779900da9be2505d68d9d8da25"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://git.kernel.org/stable/c/9ee803bfdba0cf739038dbdabdd4c02582c8f2b2"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://git.kernel.org/stable/c/6e9ff1eb7feedcf46ff2d0503759960ab58e7775"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://git.kernel.org/stable/c/12b4c5d98cd7ca46d5035a57bcd995df614c14e1"
                }
            ],
            "title": "CVE-2026-31392"
        }
    ]
}