CVE-2026-43350

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> smb: client: require a full NFS mode SID before reading mode bits<br /> <br /> parse_dacl() treats an ACE SID matching sid_unix_NFS_mode as an NFS<br /> mode SID and reads sid.sub_auth[2] to recover the mode bits.<br /> <br /> That assumes the ACE carries three subauthorities, but compare_sids()<br /> only compares min(a, b) subauthorities. A malicious server can return<br /> an ACE with num_subauth = 2 and sub_auth[] = {88, 3}, which still<br /> matches sid_unix_NFS_mode and then drives the sub_auth[2] read four<br /> bytes past the end of the ACE.<br /> <br /> Require num_subauth &gt;= 3 before treating the ACE as an NFS mode SID.<br /> This keeps the fix local to the special-SID mode path without changing<br /> compare_sids() semantics for the rest of cifsacl.