CVE-2026-64380 — smb: client: harden POSIX SID length parsing
In the Linux kernel, the following vulnerability has been resolved: smb: client: harden POSIX SID length parsing posix_info_sid_size() reads sid[1] to obtain the subauthority …
Published: 2026-07-25 · CVSS: 8.2 · CVSS 3.1
In the Linux kernel, the following vulnerability has been resolved: smb: client: harden POSIX SID length parsing posix_info_sid_size() reads sid[1] to obtain the subauthority count, but its existing boundary check still accepts buffers with only one remaining byte. Require two bytes before reading sid[1] so all client paths that reuse the helper reject truncated POSIX SIDs safely.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7