CVE-2026-43350
smb: client: require a full NFS mode SID before reading mode bits
HIGH 7.6
At a glance
- Source
- NVD
- EPSS
- EPSS 0.32 % · percentile 25 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Modified
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.
Weaknesses (CWE)
- CWE-125 — Out-of-bounds Read
References
- https://git.kernel.org/stable/c/23b54d6cc3ef30a51d984dc74364f24039ae2ecb
- https://git.kernel.org/stable/c/1592a6cd6f653f2d24572a6976c7a775b19f4940
- https://git.kernel.org/stable/c/8bd4cad3f458d11650d51c2d24b03fb1770ae6cc
- https://git.kernel.org/stable/c/b53b8e98c23310294fc45fc686db5ee860311896
- https://git.kernel.org/stable/c/c8eef12af1cc73031639ea7cf16e0b10e2536b0b
- https://git.kernel.org/stable/c/38a69f08ee82c450d3e4168707fff2e317dc3ff7
- https://git.kernel.org/stable/c/f8488c07bea2431ee12a6067d736578064fa46b4
- https://git.kernel.org/stable/c/2757ad3e4b6f9e0fed4c7739594e702abc5cab21
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H | Linux |
| CVSS 3.1 | HIGH 7.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H | NVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary) |
European references
- ENISA EUVD · EUVD-2026-28634
- GCVE · GCVE-0-2026-43350
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1333 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1298 — Multiples vulnérabilités dans les produits Siemens · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1286 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1066 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0954 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0926 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0862 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0861 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0831 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.4 < 6.6.136cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.7 < 6.12.84cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.13 < 6.18.25cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.19 < 7.0.2
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected e2f8fbfb8d09c06decde162090fac3ee220aa280 < 23b54d6cc3ef30a51d984dc74364f24039ae2ecb ; affected e2f8fbfb8d09c06decde162090fac3ee220aa280 < 1592a6cd6f653f2d24572a6976c7a775b19f4940 ; affected e2f8fbfb8d09c06decde162090fac3ee220aa280 < 8bd4cad3f458d11650d51c2d24b03fb1770ae6cc ; affected e2f8fbfb8d09c06decde162090fac3ee220aa280 < b53b8e98c23310294fc45fc686db5ee860311896 ; affected e2f8fbfb8d09c06decde162090fac3ee220aa280 < c8eef12af1cc73031639ea7cf16e0b10e2536b0b ; affected e2f8fbfb8d09c06decde162090fac3ee220aa280 < 38a69f08ee82c450d3e4168707fff2e317dc3ff7 |
| Linux · Linux | affected 5.4 ; unaffected 0 < 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.* |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |