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.
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
| Product | Fixed in | Fix | Released |
|---|---|---|---|
| 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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