{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2026-98215",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-98215",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-10-06T08:44:51.412Z",
    "updatedAt": "2026-10-19T09:15:46.038Z",
    "importedAt": "2026-10-24T01:58:41.756Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "selinux: preserve user SID across nested backing files",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nselinux: preserve user SID across nested backing files\n\nSELinux saves the user file SID in a backing-file security blob so it\nremains available after mmap() replaces vma->vm_file with a backing file.\n\nFor nested backing files (overlayfs over overlayfs, or FUSE passthrough\nbacked by overlayfs), user_file may itself be a backing file.  Its\nfsec->sid is the SID of the mounter that opened it, rather than the user\nthat opened the top-level file.  mprotect() then checks fd { use } against\nthe mounter SID.  This can incorrectly deny access without a domain\ntransition, or check the wrong target SID after one.\n\nCopy the saved user SID when user_file is a backing file.  Keep using the\nregular file SID for the first backing layer.\n\nWith two nested overlayfs mounts and SELinux enforcing,\nmprotect(PROT_READ) returns EACCES with an fd { use } denial against the\nmounter SID.  With this change, mprotect() succeeds.\n\nTested on arm64 QEMU with a small BusyBox initramfs and a purpose-built\nSELinux policy.  The original test was also repeated with Fedora Cloud\nBase 44 userspace and gave the same result.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "bc6c380c1159de52a252ed11f19a42c47f60a735",
              "status": "affected",
              "versionType": "git",
              "lessThan": "caa1b913d90d5dc07073733326d2af0f0288f089"
            },
            {
              "version": "8bacd09f12c27710228562e4d13163e58c5f4a45",
              "status": "affected",
              "versionType": "git",
              "lessThan": "6aaeec59aadcd1eafc18b049f1b759fb6b9d9569"
            },
            {
              "version": "d844702198395d3f80222777030f69db6be6b709",
              "status": "affected",
              "versionType": "git",
              "lessThan": "9d99b770e7b67b00bdef9005b928aad13e1d679b"
            },
            {
              "version": "82544d36b1729153c8aeb179e84750f0c085d3b1",
              "status": "affected",
              "versionType": "git",
              "lessThan": "ff20d16b2e8230c034e21540043df47222dcc09b"
            },
            {
              "version": "82544d36b1729153c8aeb179e84750f0c085d3b1",
              "status": "affected",
              "versionType": "git",
              "lessThan": "8c0c602202b9a4909b00bc3354e3c0355bc69e65"
            },
            {
              "version": "cd0e707a927a70cdfd8bc5a512a9719a87f5ed51",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "6.6.144",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.6.158"
            },
            {
              "version": "6.12.95",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.12.112"
            },
            {
              "version": "6.18.38",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.18.54"
            },
            {
              "version": "7.0.4",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "7.1"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "7.1",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "7.1"
            },
            {
              "version": "6.6.158",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.112",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.54",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "7.2.8",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "version": "7.3",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}