CVE-2026-74521 PUBLISHED

ksmbd: use memcmp() to compare ClientGUIDs

Assigner: Linux
Reserved: 15.08.2026 Published: 15.08.2026 Updated: 15.08.2026

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.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 to d535363299822c5caa543787b21bd5cfa3e41949 (excl.)
  • affected from e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 to e8bb506e6ef749ac0336f3e579d8d02396b7d832 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 5.15 is affected
  • unaffected from 0 to 5.15 (excl.)
  • unaffected from 7.1.8 to 7.1.* (incl.)
  • unaffected from 7.2-rc6 to * (incl.)

References