CVE-2026-43350smb: client: require a full NFS mode SID before reading mode bits
- 7.6HighCVSS base score
- 0.32%Exploitation in 30 daysEPSS · top 74% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: require a full NFS mode SID before reading mode bits parse_dacl() treats an ACE SID matching sid_unix_NFS_mode as an NFS mode SID and reads sid.sub_auth[2] to recover the mode bits. That assumes the ACE carries three subauthorities, but compare_sids() only compares min(a, b) subauthorities. A malicious server can return an ACE with num_subauth = 2 and sub_auth[] = {88, 3}, which still matches sid_unix_NFS_mode and then drives the sub_auth[2] read four bytes past the end of the ACE. Require num_subauth >= 3 before treating the ACE as an NFS mode SID. This keeps the fix local to the special-SID mode path without changing compare_sids() semantics for the rest of cifsacl.
Timeline
ID reserved
By Linux
- 7 days later
· 7 days later
Published
- 5 months later
· 5 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H |
| NVDNVD · Modified | 3.1 | High7.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H |
- EPSS (exploitation in 30 days)
- 0.32% · top 74% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.6.
Affected products
- affected e2f8fbfb8d09c06decde162090fac3ee220aa280 – < 23b54d6cc3ef30a51d984dc74364f24039ae2ecb
- affected e2f8fbfb8d09c06decde162090fac3ee220aa280 – < 1592a6cd6f653f2d24572a6976c7a775b19f4940
- affected e2f8fbfb8d09c06decde162090fac3ee220aa280 – < 8bd4cad3f458d11650d51c2d24b03fb1770ae6cc
- affected e2f8fbfb8d09c06decde162090fac3ee220aa280 – < b53b8e98c23310294fc45fc686db5ee860311896
- affected e2f8fbfb8d09c06decde162090fac3ee220aa280 – < c8eef12af1cc73031639ea7cf16e0b10e2536b0b
- affected e2f8fbfb8d09c06decde162090fac3ee220aa280 – < 38a69f08ee82c450d3e4168707fff2e317dc3ff7
- affected e2f8fbfb8d09c06decde162090fac3ee220aa280 – < f8488c07bea2431ee12a6067d736578064fa46b4
- affected e2f8fbfb8d09c06decde162090fac3ee220aa280 – < 2757ad3e4b6f9e0fed4c7739594e702abc5cab21
- affected 5.4
- unaffected < 5.4
- unaffected 5.10.259 – ≤ 5.10.*
- unaffected 5.15.210 – ≤ 5.15.*
- unaffected 6.1.175 – ≤ 6.1.*
- unaffected 6.6.136 – ≤ 6.6.*
- unaffected 6.12.84 – ≤ 6.12.*
- unaffected 6.18.25 – ≤ 6.18.*
- unaffected 7.0.2 – ≤ 7.0.*
- unaffected 7.1 – ≤ *
References
References9
- https://git.kernel.org/stable/c/23b54d6cc3ef30a51d984dc74364f24039ae2ecb (opens in a new tab)
- https://git.kernel.org/stable/c/1592a6cd6f653f2d24572a6976c7a775b19f4940 (opens in a new tab)
- https://git.kernel.org/stable/c/8bd4cad3f458d11650d51c2d24b03fb1770ae6cc (opens in a new tab)
- https://git.kernel.org/stable/c/b53b8e98c23310294fc45fc686db5ee860311896 (opens in a new tab)
- https://git.kernel.org/stable/c/c8eef12af1cc73031639ea7cf16e0b10e2536b0b (opens in a new tab)
- https://git.kernel.org/stable/c/38a69f08ee82c450d3e4168707fff2e317dc3ff7 (opens in a new tab)
- https://git.kernel.org/stable/c/f8488c07bea2431ee12a6067d736578064fa46b4 (opens in a new tab)
- https://git.kernel.org/stable/c/2757ad3e4b6f9e0fed4c7739594e702abc5cab21 (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-28634 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-43350)Record last updated .