{
    "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-2026-31788",
        "tracking": {
            "current_release_date": "2026-04-02T16:01:30.094390Z",
            "generator": {
                "date": "2026-02-17T15:00:00Z",
                "engine": {
                    "name": "V.E.L.M.A",
                    "version": "1.7"
                }
            },
            "id": "CVE-2026-31788",
            "initial_release_date": "2026-03-25T00:45:04.600915Z",
            "revision_history": [
                {
                    "date": "2026-03-25T00:45:04.600915Z",
                    "number": "1",
                    "summary": "CVE created.| Source created.| CVE status created. (valid)| Products connected (2)."
                },
                {
                    "date": "2026-03-25T00:45:14.963741Z",
                    "number": "2",
                    "summary": "NCSC Score created."
                },
                {
                    "date": "2026-03-25T10:41:40.085815Z",
                    "number": "3",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| Products created (7).| Products connected (3).| References created (5)."
                },
                {
                    "date": "2026-03-25T10:41:51.827524Z",
                    "number": "4",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-25T11:33:46.208058Z",
                    "number": "5",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| References created (5)."
                },
                {
                    "date": "2026-03-25T11:39:07.806643Z",
                    "number": "6",
                    "summary": "References created (5)."
                },
                {
                    "date": "2026-03-25T12:25:08.951503Z",
                    "number": "7",
                    "summary": "References created (5)."
                },
                {
                    "date": "2026-03-25T13:15:22.397304Z",
                    "number": "8",
                    "summary": "Source created.| CVE status created. (valid)| Products connected (1).| Product Identifiers created (1).| References created (3)."
                },
                {
                    "date": "2026-03-25T13:15:27.024206Z",
                    "number": "9",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-26T00:54:15.317685Z",
                    "number": "10",
                    "summary": "Source connected.| CVE status created. (valid)| EPSS created."
                },
                {
                    "date": "2026-03-26T00:54:23.344827Z",
                    "number": "11",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-26T06:45:53.654885Z",
                    "number": "12",
                    "summary": "Description created for source."
                },
                {
                    "date": "2026-03-26T17:25:48.857512Z",
                    "number": "13",
                    "summary": "References created (1)."
                },
                {
                    "date": "2026-03-26T17:39:08.198593Z",
                    "number": "14",
                    "summary": "References created (1)."
                },
                {
                    "date": "2026-03-30T08:25:19.538953Z",
                    "number": "15",
                    "summary": "References created (1)."
                },
                {
                    "date": "2026-03-30T08:25:28.642020Z",
                    "number": "16",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-04-02T15:27:29.753059Z",
                    "number": "17",
                    "summary": "CVSS created."
                },
                {
                    "date": "2026-04-02T15:27:32.543786Z",
                    "number": "18",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-04-02T15:40:17.184347Z",
                    "number": "19",
                    "summary": "CVSS created.| Products created (6).| Products connected (3).| Products removed (5).| References created (1)."
                },
                {
                    "date": "2026-04-02T15:40:30.012978Z",
                    "number": "20",
                    "summary": "NCSC Score updated."
                }
            ],
            "status": "interim",
            "version": "20"
        }
    },
    "product_tree": {
        "branches": [
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:git/1c5de1939c204bde9cce87f4eb3d26e9f9eb732b|<1879319d790f7d57622cdc22807b60ea78b56b6d",
                                "product": {
                                    "name": "vers:git/1c5de1939c204bde9cce87f4eb3d26e9f9eb732b|<1879319d790f7d57622cdc22807b60ea78b56b6d",
                                    "product_id": "CSAFPID-5984997"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:git/1c5de1939c204bde9cce87f4eb3d26e9f9eb732b|<389bae9a4409934e8b8d4dbdaaf02a3ae71cf8e4",
                                "product": {
                                    "name": "vers:git/1c5de1939c204bde9cce87f4eb3d26e9f9eb732b|<389bae9a4409934e8b8d4dbdaaf02a3ae71cf8e4",
                                    "product_id": "CSAFPID-5984999"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:git/1c5de1939c204bde9cce87f4eb3d26e9f9eb732b|<453b8fb68f3641fea970db88b7d9a153ed2a37e8",
                                "product": {
                                    "name": "vers:git/1c5de1939c204bde9cce87f4eb3d26e9f9eb732b|<453b8fb68f3641fea970db88b7d9a153ed2a37e8",
                                    "product_id": "CSAFPID-5985001"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:git/1c5de1939c204bde9cce87f4eb3d26e9f9eb732b|<78432d8f0372c71c518096395537fa12be7ff24e",
                                "product": {
                                    "name": "vers:git/1c5de1939c204bde9cce87f4eb3d26e9f9eb732b|<78432d8f0372c71c518096395537fa12be7ff24e",
                                    "product_id": "CSAFPID-5984998"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:git/1c5de1939c204bde9cce87f4eb3d26e9f9eb732b|<87a803edb2ded911cb587c53bff179d2a2ed2a28",
                                "product": {
                                    "name": "vers:git/1c5de1939c204bde9cce87f4eb3d26e9f9eb732b|<87a803edb2ded911cb587c53bff179d2a2ed2a28",
                                    "product_id": "CSAFPID-5984996"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:git/1c5de1939c204bde9cce87f4eb3d26e9f9eb732b|<cbede2e833da1893afbea9b3ff29b5dda23a4a91",
                                "product": {
                                    "name": "vers:git/1c5de1939c204bde9cce87f4eb3d26e9f9eb732b|<cbede2e833da1893afbea9b3ff29b5dda23a4a91",
                                    "product_id": "CSAFPID-5985000"
                                }
                            },
                            {
                                "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:semver/<2.6.37",
                                "product": {
                                    "name": "vers:semver/<2.6.37",
                                    "product_id": "CSAFPID-1287118"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/2.6.37",
                                "product": {
                                    "name": "vers:unknown/2.6.37",
                                    "product_id": "CSAFPID-1287117"
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/7.0-rc6|<=*",
                                "product": {
                                    "name": "vers:unknown/7.0-rc6|<=*",
                                    "product_id": "CSAFPID-5971751"
                                }
                            }
                        ],
                        "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-1459796",
                                    "product_identification_helper": {
                                        "cpe": "cpe:/o:xen:xen:-"
                                    }
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "Open Source Xen"
                    }
                ],
                "category": "vendor",
                "name": "Open Source"
            },
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "branches": [
                                    {
                                        "category": "product_version_range",
                                        "name": "vers:deb/unknown",
                                        "product": {
                                            "name": "vers:deb/unknown",
                                            "product_id": "CSAFPID-2036024"
                                        }
                                    }
                                ],
                                "category": "product_name",
                                "name": "linux"
                            }
                        ],
                        "category": "product_family",
                        "name": "bookworm"
                    },
                    {
                        "branches": [
                            {
                                "branches": [
                                    {
                                        "category": "product_version_range",
                                        "name": "vers:deb/unknown",
                                        "product": {
                                            "name": "vers:deb/unknown",
                                            "product_id": "CSAFPID-2036021"
                                        }
                                    }
                                ],
                                "category": "product_name",
                                "name": "linux"
                            }
                        ],
                        "category": "product_family",
                        "name": "bullseye"
                    }
                ],
                "category": "vendor",
                "name": "Debian"
            }
        ]
    },
    "vulnerabilities": [
        {
            "cve": "CVE-2026-31788",
            "notes": [
                {
                    "category": "description",
                    "text": "In the Linux kernel, the following vulnerability has been resolved:\n\nxen/privcmd: restrict usage in unprivileged domU\n\nThe Xen privcmd driver allows to issue arbitrary hypercalls from\nuser space processes. This is normally no problem, as access is\nusually limited to root and the hypervisor will deny any hypercalls\naffecting other domains.\n\nIn case the guest is booted using secure boot, however, the privcmd\ndriver would be enabling a root user process to modify e.g. kernel\nmemory contents, thus breaking the secure boot feature.\n\nThe only known case where an unprivileged domU is really needing to\nuse the privcmd driver is the case when it is acting as the device\nmodel for another guest. In this case all hypercalls issued via the\nprivcmd driver will target that other guest.\n\nFortunately the privcmd driver can already be locked down to allow\nonly hypercalls targeting a specific domain, but this mode can be\nactivated from user land only today.\n\nThe target domain can be obtained from Xenstore, so when not running\nin dom0 restrict the privcmd driver to that target domain from the\nbeginning, resolving the potential problem of breaking secure boot.\n\nThis is XSA-482\n\n---\nV2:\n- defer reading from Xenstore if Xenstore isn't ready yet (Jan Beulich)\n- wait in open() if target domain isn't known yet\n- issue message in case no target domain found (Jan Beulich)",
                    "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/31xxx/CVE-2026-31788.json"
                },
                {
                    "category": "description",
                    "text": "In the Linux kernel, the following vulnerability has been resolved:\n\nxen/privcmd: restrict usage in unprivileged domU\n\nThe Xen privcmd driver allows to issue arbitrary hypercalls from\nuser space processes. This is normally no problem, as access is\nusually limited to root and the hypervisor will deny any hypercalls\naffecting other domains.\n\nIn case the guest is booted using secure boot, however, the privcmd\ndriver would be enabling a root user process to modify e.g. kernel\nmemory contents, thus breaking the secure boot feature.\n\nThe only known case where an unprivileged domU is really needing to\nuse the privcmd driver is the case when it is acting as the device\nmodel for another guest. In this case all hypercalls issued via the\nprivcmd driver will target that other guest.\n\nFortunately the privcmd driver can already be locked down to allow\nonly hypercalls targeting a specific domain, but this mode can be\nactivated from user land only today.\n\nThe target domain can be obtained from Xenstore, so when not running\nin dom0 restrict the privcmd driver to that target domain from the\nbeginning, resolving the potential problem of breaking secure boot.\n\nThis is XSA-482\n\n---\nV2:\n- defer reading from Xenstore if Xenstore isn't ready yet (Jan Beulich)\n- wait in open() if target domain isn't known yet\n- issue message in case no target domain found (Jan Beulich)",
                    "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-31788"
                },
                {
                    "category": "description",
                    "text": "In the Linux kernel, the following vulnerability has been resolved:  xen/privcmd: restrict usage in unprivileged domU  The Xen privcmd driver allows to issue arbitrary hypercalls from user space processes. This is normally no problem, as access is usually limited to root and the hypervisor will deny any hypercalls affecting other domains.  In case the guest is booted using secure boot, however, the privcmd driver would be enabling a root user process to modify e.g. kernel memory contents, thus breaking the secure boot feature.  The only known case where an unprivileged domU is really needing to use the privcmd driver is the case when it is acting as the device model for another guest. In this case all hypercalls issued via the privcmd driver will target that other guest.  Fortunately the privcmd driver can already be locked down to allow only hypercalls targeting a specific domain, but this mode can be activated from user land only today.  The target domain can be obtained from Xenstore, so when not running in dom0 restrict the privcmd driver to that target domain from the beginning, resolving the potential problem of breaking secure boot.  This is XSA-482  --- V2: - defer reading from Xenstore if Xenstore isn't ready yet (Jan Beulich) - wait in open() if target domain isn't known yet - issue message in case no target domain found (Jan Beulich)",
                    "title": "debian - https://security-tracker.debian.org/tracker/CVE-2026-31788"
                },
                {
                    "category": "other",
                    "text": "0.00033",
                    "title": "EPSS"
                },
                {
                    "category": "other",
                    "text": "3.7",
                    "title": "NCSC Score"
                },
                {
                    "category": "other",
                    "text": "The value of the most recent EPSS score, Is related to a product by vendor Linux, Is related to a product by vendor Open Source",
                    "title": "NCSC Score top decreasing factors"
                }
            ],
            "product_status": {
                "known_affected": [
                    "CSAFPID-2036021",
                    "CSAFPID-2036024",
                    "CSAFPID-1459796",
                    "CSAFPID-1287117",
                    "CSAFPID-5984996",
                    "CSAFPID-5984997",
                    "CSAFPID-5984998",
                    "CSAFPID-5984999",
                    "CSAFPID-5985000",
                    "CSAFPID-5985001"
                ],
                "known_not_affected": [
                    "CSAFPID-5904647",
                    "CSAFPID-5904654",
                    "CSAFPID-5904671",
                    "CSAFPID-5905005",
                    "CSAFPID-5905006",
                    "CSAFPID-1287118",
                    "CSAFPID-5971751"
                ]
            },
            "references": [
                {
                    "category": "external",
                    "summary": "Source - debian",
                    "url": "https://security-tracker.debian.org/tracker/CVE-2026-31788"
                },
                {
                    "category": "external",
                    "summary": "Source - cveprojectv5",
                    "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/31xxx/CVE-2026-31788.json"
                },
                {
                    "category": "external",
                    "summary": "Source - nvd",
                    "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-31788"
                },
                {
                    "category": "external",
                    "summary": "Source - certbundde",
                    "url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-0855.json"
                },
                {
                    "category": "external",
                    "summary": "Source - first",
                    "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://git.kernel.org/stable/c/87a803edb2ded911cb587c53bff179d2a2ed2a28"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://git.kernel.org/stable/c/1879319d790f7d57622cdc22807b60ea78b56b6d"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://git.kernel.org/stable/c/78432d8f0372c71c518096395537fa12be7ff24e"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://git.kernel.org/stable/c/389bae9a4409934e8b8d4dbdaaf02a3ae71cf8e4"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://git.kernel.org/stable/c/cbede2e833da1893afbea9b3ff29b5dda23a4a91"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "http://xenbits.xen.org/xsa/advisory-482.html"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "http://www.openwall.com/lists/oss-security/2026/03/24/2"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "http://www.openwall.com/lists/oss-security/2026/03/24/3"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "http://www.openwall.com/lists/oss-security/2026/03/24/4"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "http://www.openwall.com/lists/oss-security/2026/03/24/5"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-0855.json"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-0855"
                },
                {
                    "category": "external",
                    "summary": "Reference - certbundde",
                    "url": "https://xenbits.xen.org/xsa/advisory-482.html"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "http://www.openwall.com/lists/oss-security/2026/03/26/4"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://git.kernel.org/stable/c/453b8fb68f3641fea970db88b7d9a153ed2a37e8"
                }
            ],
            "scores": [
                {
                    "cvss_v3": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H",
                        "baseScore": 8.2,
                        "baseSeverity": "HIGH"
                    },
                    "products": [
                        "CSAFPID-1287117",
                        "CSAFPID-1459796",
                        "CSAFPID-2036021",
                        "CSAFPID-2036024",
                        "CSAFPID-5984996",
                        "CSAFPID-5984997",
                        "CSAFPID-5984998",
                        "CSAFPID-5984999",
                        "CSAFPID-5985000",
                        "CSAFPID-5985001"
                    ]
                }
            ],
            "title": "CVE-2026-31788"
        }
    ]
}