GHSA-M2GQ-X88Q-682F

Vulnerability from github – Published: 2026-08-10 15:33 – Updated: 2026-08-14 00:31
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: validate ACE size against SID sub-authorities

set_ntacl_dacl() validates sid.num_subauth before copying an ACE, but does not verify that the declared ACE size contains all sub-authorities described by that field. An undersized ACE can therefore be copied and later make the POSIX ACL deduplication walk inspect data beyond the copied ACE boundary.

The existing initial bound check is also too small. It only ensures that the ACE size field is accessible before set_ntacl_dacl() reads sid.num_subauth farther into the input buffer.

Require enough input for the fixed SID header before accessing num_subauth, reject ACEs smaller than that header, and skip ACEs whose declared size cannot contain the complete SID. This makes the validation consistent with the other ACE walk paths.

Severity
8.8 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2026-68097"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-10T13:19:54Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: validate ACE size against SID sub-authorities\n\nset_ntacl_dacl() validates sid.num_subauth before copying an ACE, but\ndoes not verify that the declared ACE size contains all sub-authorities\ndescribed by that field. An undersized ACE can therefore be copied\nand later make the POSIX ACL deduplication walk inspect data beyond\nthe copied ACE boundary.\n\nThe existing initial bound check is also too small. It only ensures\nthat the ACE size field is accessible before set_ntacl_dacl() reads\nsid.num_subauth farther into the input buffer.\n\nRequire enough input for the fixed SID header before accessing\nnum_subauth, reject ACEs smaller than that header, and skip ACEs\nwhose declared size cannot contain the complete SID. This makes the\nvalidation consistent with the other ACE walk paths.",
  "id": "GHSA-m2gq-x88q-682f",
  "modified": "2026-08-14T00:31:51Z",
  "published": "2026-08-10T15:33:35Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68097"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/337022d9dfac441c3b35e4455a51aa981996e02e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5152c6d49e3fd4e9f2e857c57527aead752f1f87"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/61fd3559199f7fa693dcbff35e59477e24af041a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/62d80d7c2d9428085e7458ad4c06ca8c0984039b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b7cb5bf0855470799f12da825de91e48951b3876"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.