CVE-2026-74521

linux: In the Linux kernel, the following vulnerability has been resolved: ksmbd: use memcmp() to compare ClientGUIDs Clie...

CVE-2026-74521 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-74521, released August 16, 2026. It is not reported as exploited. Patch Radar priority: Urgent.

Urgent
CVSS
9.1
critical
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0041
35th percentile

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.

Where it's fixed

ProductFixed inFixReleased
Linux
linux · Debian 12.15 (bookworm) 6.1.190-1 DEBIAN-CVE-2026-74521 Aug 16, 2026
linux · Debian 13.5 (trixie) 6.12.111-1 DEBIAN-CVE-2026-74521 Aug 16, 2026
linux · Debian 14 7.1.8-1 DEBIAN-CVE-2026-74521 Aug 16, 2026
linux-6.12 · Debian 12.15 (bookworm) 6.12.111-1~deb12u1 DEBIAN-CVE-2026-74521 Aug 16, 2026

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