CVE-2026-43350smb: client: require a full NFS mode SID before reading mode bits
Updated under an hour ago ()
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It affects Linux and 2 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 7.6 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Modified
- Record last updated
- Oct 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from e2f8fbfb8d09c06decde162090fac3ee220aa280 before 23b54d6cc3ef30a51d984dc74364f24039ae2ecb; from e2f8fbfb8d09c06decde162090fac3ee220aa280 before 1592a6cd6f653f2d24572a6976c7a775b19f4940; from e2f8fbfb8d09c06decde162090fac3ee220aa280 before 8bd4cad3f458d11650d51c2d24b03fb1770ae6cc; from e2f8fbfb8d09c06decde162090fac3ee220aa280 before b53b8e98c23310294fc45fc686db5ee860311896; from e2f8fbfb8d09c06decde162090fac3ee220aa280 before c8eef12af1cc73031639ea7cf16e0b10e2536b0b; from e2f8fbfb8d09c06decde162090fac3ee220aa280 before 38a69f08ee82c450d3e4168707fff2e317dc3ff7; from e2f8fbfb8d09c06decde162090fac3ee220aa280 before f8488c07bea2431ee12a6067d736578064fa46b4; from e2f8fbfb8d09c06decde162090fac3ee220aa280 before 2757ad3e4b6f9e0fed4c7739594e702abc5cab21 | CNA record |
Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem siemens:simatic_s7_1500_tm_mfp_gnu_linux_subsystem (from the name) | all versions | CISA ADP |
linux linux_kernel linux:linux_kernel | from 5.4 before 6.6.136; from 6.7 before 6.12.84; from 6.13 before 6.18.25; from 6.19 before 7.0.2 | NVD |
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/b53b8e98c23310294fc45fc686db5ee860311896patch
- https://git.kernel.org/stable/c/c8eef12af1cc73031639ea7cf16e0b10e2536b0bpatch
- https://git.kernel.org/stable/c/38a69f08ee82c450d3e4168707fff2e317dc3ff7patch
- https://git.kernel.org/stable/c/f8488c07bea2431ee12a6067d736578064fa46b4patch
- https://git.kernel.org/stable/c/2757ad3e4b6f9e0fed4c7739594e702abc5cab21patch
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.