CVE-2026-64393 — CRITICAL (9.1)

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: run set info with opener credentials SMB2 SET_INFO handlers call path-based VFS helpers after checking the access mask granted to the SMB handle. Those helpers perform their owner, inode permission and LSM checks using the current ksmbd worker credentials. Run the complete SET_INFO dispatch with the credentials captured when the handle was opened. This also removes the separate security information credential setup and keeps all SET_INFO classes under one credential scope. Direct override_creds() is used because it can nest with the request credential overrides already used by rename and link helpers.

CVSS Score

9.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

HIGH

Availability

HIGH

References

FAQ

What is CVE-2026-64393?

CVE-2026-64393 is a vulnerability with a CVSS score of 9.1 (CRITICAL). In the Linux kernel, the following vulnerability has been resolved: ksmbd: run set info with opener credentials SMB2 SET_INFO handlers call path-based VFS helpers after checking the access mask gran...

How severe is CVE-2026-64393?

CVE-2026-64393 has been rated CRITICAL with a CVSS base score of 9.1/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2026-64393?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.