CVE-2026-68097 json
ksmbd: validate ACE size against SID sub-authorities
published 2026-08-10 2 mo ago modified 2026-10-03 36 d ago also EUVD-2026-55478
- cvss
- 8.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 39%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- Linux Linux 6.1.189, 6.6.148, 6.12.101, 6.18.42, 7.1.6, 7.2
- linux Debian 12 6.1.190-1
- linux Debian 13 6.12.101-1
- linux Debian 14 7.1.6-1
- linux-6.12 Debian 12 6.12.101-1~deb12u1
debian advisories DEBIAN-CVE-2026-68097
- linux Ubuntu 24.04 LTS 6.8.0-147.147
- linux Ubuntu 26.04 LTS 7.0.0-38.38
- linux-aws Ubuntu 24.04 LTS 6.8.0-1067.70
- linux-aws Ubuntu 26.04 LTS 7.0.0-1014.14
- linux-gcp Ubuntu 24.04 LTS 6.8.0-1071.79
- linux-gcp Ubuntu 26.04 LTS 7.0.0-1014.14
- linux-gke Ubuntu 24.04 LTS 6.8.0-1066.74
- linux-gke Ubuntu 26.04 LTS 7.0.0-1008.9
ubuntu advisories UBUNTU-CVE-2026-68097
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- git.kernel.org/stable/c/5a2d9fe0e87c71baa0aaa1cfc1361892fcd1ece0 commit
- git.kernel.org/stable/c/b7cb5bf0855470799f12da825de91e48951b3876 commit
- git.kernel.org/stable/c/62d80d7c2d9428085e7458ad4c06ca8c0984039b commit
- git.kernel.org/stable/c/337022d9dfac441c3b35e4455a51aa981996e02e commit
- git.kernel.org/stable/c/61fd3559199f7fa693dcbff35e59477e24af041a commit
- git.kernel.org/stable/c/5152c6d49e3fd4e9f2e857c57527aead752f1f87 commit
Exploit prediction
0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected products
- Linux Linux
Classification
- Technology feeds
References
- git.kernel.org /stable/c/5a2d9fe0e87c71baa0aaa1cfc1361892fcd1ece0
- git.kernel.org /stable/c/b7cb5bf0855470799f12da825de91e48951b3876
- git.kernel.org /stable/c/62d80d7c2d9428085e7458ad4c06ca8c0984039b
- git.kernel.org /stable/c/337022d9dfac441c3b35e4455a51aa981996e02e
- git.kernel.org /stable/c/61fd3559199f7fa693dcbff35e59477e24af041a
- git.kernel.org /stable/c/5152c6d49e3fd4e9f2e857c57527aead752f1f87
Sources
- CVE List CVE-2026-68097
- NVD CVE-2026-68097
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.