CVE-2026-64393
CriticalCVSS 9.1Exploitation Probability (EPSS)
Low risk39th percentile - higher than 39% of all known CVEs
Summary
In the Linux kernel, the ksmbd filesystem runs SET_INFO operations with the current ksmbd worker credentials instead of the credentials of the user who opened the handle. This can bypass owner-based and LSM access controls.
Risk Assessment
An attacker can modify file attributes or perform other SET_INFO operations with higher privileges than intended, compromising data integrity and confidentiality.
Recommendation
Apply the Linux kernel patch that runs SET_INFO operations with the credentials captured when the handle was opened.
Original NVD description (English source)
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.