Riskcovery

CVE-2026-74521

ksmbd: use memcmp() to compare ClientGUIDs

State
Published
Severity
9.1 Critical
Published
Aug 15, 2026
Updated
Oct 3, 2026
Reserved
Aug 15, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
3.19.1 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NLinux

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 to before 7bde6f181fa307d2cc1ec2b0313ac8e9811c8232Affected
  • e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 to before 5a0367bf5ce420be7b19936def2e90adcf32a683Affected
  • e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 to before ba2a5b66f1d414eb8403d655f8813783892cfc85Affected
  • e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 to before a386c83043015a703e227775f778e40343f45911Affected
  • e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 to before d535363299822c5caa543787b21bd5cfa3e41949Affected
  • e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 to before e8bb506e6ef749ac0336f3e579d8d02396b7d832Affected
LinuxLinux
  • 5.15Affected
  • before 5.15Not affected
  • 6.1.189 through 6.1.*Not affected
  • 6.6.158 through 6.6.*Not affected
  • 6.12.111 through 6.12.*Not affected
  • 6.18.53 through 6.18.*Not affected
  • 7.1.8 through 7.1.*Not affected
  • 7.2 and laterNot affected

References

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