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Review reviewCritical

CVE-2026-64393

Linux

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 c...

CVSS
9.1
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.07.25
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 9.1

Vulnerability overview

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 c...

Affected product and versions

Product
Linux
Affected versions
>= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 5cbabf3a71575cd31bc7785d92d4ab42338a654b, >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < b35afd5cf8fab236ef21117e42ee45691d4ffa7b, >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 0ce682867fd506f61f40c76bde7e4205bde34e87, >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 20ee516a62989a8d505ee432f9e59525ea23984e, >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 8cc9ec711f5255167247a9ab6a7179b787426ed7, >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < b383bcad3d2fe634b26efbce53e22bbb5753a520, >= 5.15
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
CWE
Not available
CVE-2026-64393 — Linux | SECUFOCUS NOW