{
  "cveId": "CVE-2026-31611",
  "url": "https://patchblox.com/security/cve/CVE-2026-31611",
  "summary": "CVE-2026-31611 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-31611, released May 15, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "ksmbd: require 3 sub-authorities before reading sub_auth[2]",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  ksmbd: require 3 sub-authorities before reading sub_auth[2]  parse_dacl() compares each ACE SID against sid_unix_NFS_mode and on match reads sid.sub_auth[2] as the file mode.  If sid_unix_NFS_mode is the prefix S-1-5-88-3 with num_subauth = 2 then compare_sids() compares only min(num_subauth, 2) sub-authorities so a client SID with num_subauth = 2 and sub_auth = {88, 3} will match.  If num_subauth = 2 and the ACE is placed at the very end of the security descriptor, sub_auth[2] will be  4 bytes past end_of_acl.  The out-of-band bytes will then be masked to the low 9 bits and applied as the file\u0027s POSIX mode, probably not something that is good to have happen.  Fix this up by forcing the SID to actually carry a third sub-authority before reading it at all.",
  "published": "2026-04-24T15:16:40Z",
  "severity": "Moderate",
  "cvss": 8.6,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H",
  "epss": 0.00375,
  "epssPercentile": 0.31696,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-31611",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.1.176-1",
      "fix": "DEBIAN-CVE-2026-31611",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-31611",
      "released": "2026-05-15T16:01:09Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.85-1",
      "fix": "DEBIAN-CVE-2026-31611",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-31611",
      "released": "2026-05-15T16:01:09Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "6.19.14-1",
      "fix": "DEBIAN-CVE-2026-31611",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-31611",
      "released": "2026-05-15T16:01:09Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T13:31:49Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}