CVE-2026-74521

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.

Package Linux Kernel
Published 2026-08-15
Last modified 2026-08-15
Patch available
Yes

Affected versions

Linux kernel versions 5.15 and later are affected. Fixed in 7.1.8, 7.2-rc6 and their respective stable series.

Affected from
≥ 5.15
Fixed in
✓ 7.1.8 7.1.x ✓ 7.2-rc6

References

2 total

Frequently asked questions

  • What is CVE-2026-74521?

    CVE-2026-74521 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.15 onward and has been patched in 7.1.8 and 7.2-rc6. CVE-2026-74521 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • Is there a patch available for CVE-2026-74521?

    Yes. CVE-2026-74521 has been patched. Fixed versions include 7.1.8 and 7.2-rc6. If you are running Linux kernel 5.15 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-74521 actively exploited?

    No. CVE-2026-74521 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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