CVE-2026-43350: Linux Kernel

High severity, CVSS 7.6. EPSS: 0.4% chance of exploitation in the next 30 days.

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.

Affected products

• Linux Linux Kernel: from 5.4, before 6.6.136 (fixed in 6.6.136); from 6.7, before 6.12.84 (fixed in 6.12.84); from 6.13, before 6.18.25 (fixed in 6.18.25); from 6.19, before 7.0.2 (fixed in 7.0.2)

Published 2026-05-08. Last modified 2026-06-19.