Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: use memcmp() to compare ClientGUIDs ClientGUID is a fixed-size binary value and can contain embedded NUL bytes. strncmp() stops comparing at the first NUL byte, so different ClientGUID values can incorrectly be treated as equal. Use memcmp() in SMB3 multichannel session binding and FSCTL_VALIDATE_NEGOTIATE_INFO to compare all SMB2_CLIENT_GUID_SIZE bytes.
References6
- git.kernel.org/stable/c/5a0367bf5ce420be7b19936def2e90adcf32a683
- git.kernel.org/stable/c/7bde6f181fa307d2cc1ec2b0313ac8e9811c8232
- git.kernel.org/stable/c/a386c83043015a703e227775f778e40343f45911
- git.kernel.org/stable/c/ba2a5b66f1d414eb8403d655f8813783892cfc85
- git.kernel.org/stable/c/d535363299822c5caa543787b21bd5cfa3e41949
- git.kernel.org/stable/c/e8bb506e6ef749ac0336f3e579d8d02396b7d832
Metrics
- CVSS 3.1
-
9.1
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - EPSS — exploit probability
- 0% percentile: 35 · as of 11 November 2026
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.