{
  "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-2025-39817",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-39817",
    "idYear": 2025,
    "status": "PUBLISHED",
    "publishedAt": "2025-09-16T13:00:17.776Z",
    "updatedAt": "2026-08-05T12:05:23.813Z",
    "importedAt": "2026-10-24T01:57:34.152Z",
    "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": "efivarfs: Fix slab-out-of-bounds in efivarfs_d_compare",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nefivarfs: Fix slab-out-of-bounds in efivarfs_d_compare\n\nObserved on kernel 6.6 (present on master as well):\n\n  BUG: KASAN: slab-out-of-bounds in memcmp+0x98/0xd0\n  Call trace:\n   kasan_check_range+0xe8/0x190\n   __asan_loadN+0x1c/0x28\n   memcmp+0x98/0xd0\n   efivarfs_d_compare+0x68/0xd8\n   __d_lookup_rcu_op_compare+0x178/0x218\n   __d_lookup_rcu+0x1f8/0x228\n   d_alloc_parallel+0x150/0x648\n   lookup_open.isra.0+0x5f0/0x8d0\n   open_last_lookups+0x264/0x828\n   path_openat+0x130/0x3f8\n   do_filp_open+0x114/0x248\n   do_sys_openat2+0x340/0x3c0\n   __arm64_sys_openat+0x120/0x1a0\n\nIf dentry->d_name.len < EFI_VARIABLE_GUID_LEN , 'guid' can become\nnegative, leadings to oob. The issue can be triggered by parallel\nlookups using invalid filename:\n\n  T1\t\t\tT2\n  lookup_open\n   ->lookup\n    simple_lookup\n     d_add\n     // invalid dentry is added to hash list\n\n\t\t\tlookup_open\n\t\t\t d_alloc_parallel\n\t\t\t  __d_lookup_rcu\n\t\t\t   __d_lookup_rcu_op_compare\n\t\t\t    hlist_bl_for_each_entry_rcu\n\t\t\t    // invalid dentry can be retrieved\n\t\t\t     ->d_compare\n\t\t\t      efivarfs_d_compare\n\t\t\t      // oob\n\nFix it by checking 'guid' before cmp.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "da27a24383b2b10bf6ebd0db29b325548aafecb4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "0f63fbabeaaaaaaf5b742a2f4c1b4590d50bf1f6"
            },
            {
              "version": "da27a24383b2b10bf6ebd0db29b325548aafecb4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "794399019301944fd6d2e0d7a51b3327e26c410e"
            },
            {
              "version": "da27a24383b2b10bf6ebd0db29b325548aafecb4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "568e7761279b99c6daa3002290fd6d8047ddb6d2"
            },
            {
              "version": "da27a24383b2b10bf6ebd0db29b325548aafecb4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "d7f5e35e70507d10cbaff5f9e194ed54c4ee14f7"
            },
            {
              "version": "da27a24383b2b10bf6ebd0db29b325548aafecb4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "925599eba46045930b850a98ae594d2e3028ac40"
            },
            {
              "version": "da27a24383b2b10bf6ebd0db29b325548aafecb4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "c2925cd6207079c3f4d040d082515db78d63afbf"
            },
            {
              "version": "da27a24383b2b10bf6ebd0db29b325548aafecb4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "71581a82f38e5a4d807d71fc1bb59aead80ccf95"
            },
            {
              "version": "da27a24383b2b10bf6ebd0db29b325548aafecb4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "a6358f8cf64850f3f27857b8ed8c1b08cfc4685c"
            },
            {
              "version": "688289c4b745c018b3449b4b4c5a2030083c8eaf",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "3.8.2",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "3.9"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "3.9",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "3.9"
            },
            {
              "version": "5.4.298",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.4.*"
            },
            {
              "version": "5.10.242",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.15.191",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "6.1.150",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "version": "6.6.104",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.45",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.16.5",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.16.*"
            },
            {
              "version": "6.17",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}