Vulnerability in Linux

CVE-2026-64393

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.

EPSS: 0.005 (39.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.

Affected products

References

Frequently asked questions

What is CVE-2026-64393?
CVE-2026-64393 is a critical-severity vulnerability in Linux. CVSS score: 9.1/10. Published 2026-07-25.
How severe is CVE-2026-64393?
Critical severity. CVSS v3 base score is 9.1 out of 10.