CVE-2026-64391
CRITICAL severity · CVSS 9.8
9.8CVSS CRITICAL
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: use opener credentials for ADS I/O Alternate data streams are stored as xattrs. Unlike regular file I/O, their read and write paths therefore call VFS xattr helpers which recheck inode permissions and LSM policy using the current task credentials. Run ADS I/O with the credentials captured when the SMB handle was opened.
Impact & exploitability
Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
Exploit probability (EPSS)0%
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products we track (1)
Recommendation
Apply the vendor fix promptly. Open any affected product above for its exact safe version.
Official patch: https://git.kernel.org/stable/c/2b4592cea214683de0f2ce6f8c22c097fb0ea1ab ↗
Additional information
- NVD record
- https://git.kernel.org/stable/c/2b4592cea214683de0f2ce6f8c22c097fb0ea1abPatch
- https://git.kernel.org/stable/c/52a56cf53ec834c44ac1b4d16d585f26613ee5cePatch
- https://git.kernel.org/stable/c/a8f5d39971bbad9340d49cd41b0e2da9452a649dPatch
- https://git.kernel.org/stable/c/baa5e094886fffa7e6272edcb5e08be5ce28262cPatch
- https://git.kernel.org/stable/c/222c4c52c3af2d0f68de31182710df3508a31095
- https://git.kernel.org/stable/c/2ad5509dd576ae16d252d4698daf03002f9e0234