CVE-2026-74521

See a problem?
Please try reporting it to the source first.
Source
https://cve.org/CVERecord?id=CVE-2026-74521
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74521.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-74521
Downstream
Published
2026-08-15T12:27:39Z
Modified
2026-10-05T02:30:22Z
Severity
  • 9.1 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
Summary
ksmbd: use memcmp() to compare ClientGUIDs
Details

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.

Database specific 
{
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74521.json"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9
Fixed
7bde6f181fa307d2cc1ec2b0313ac8e9811c8232
Fixed
5a0367bf5ce420be7b19936def2e90adcf32a683
Fixed
ba2a5b66f1d414eb8403d655f8813783892cfc85
Fixed
a386c83043015a703e227775f778e40343f45911
Fixed
d535363299822c5caa543787b21bd5cfa3e41949
Fixed
e8bb506e6ef749ac0336f3e579d8d02396b7d832

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74521.json"

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
5.15.0
Fixed
6.1.189
Type
ECOSYSTEM
Events
Introduced
6.2.0
Fixed
6.6.158
Type
ECOSYSTEM
Events
Introduced
6.7.0
Fixed
6.12.111
Type
ECOSYSTEM
Events
Introduced
6.13.0
Fixed
6.18.53
Type
ECOSYSTEM
Events
Introduced
6.19.0
Fixed
7.1.8

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74521.json"