Vulnerability Description
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.
CVSS Score
CRITICAL
References
- https://git.kernel.org/stable/c/2b4592cea214683de0f2ce6f8c22c097fb0ea1ab
- https://git.kernel.org/stable/c/52a56cf53ec834c44ac1b4d16d585f26613ee5ce
- https://git.kernel.org/stable/c/a8f5d39971bbad9340d49cd41b0e2da9452a649d
- https://git.kernel.org/stable/c/baa5e094886fffa7e6272edcb5e08be5ce28262c
FAQ
What is CVE-2026-64391?
CVE-2026-64391 is a vulnerability with a CVSS score of 9.8 (CRITICAL). 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 wri...
How severe is CVE-2026-64391?
CVE-2026-64391 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-64391?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.