CVE-2026-64391

critical

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.

References

https://git.kernel.org/stable/c/baa5e094886fffa7e6272edcb5e08be5ce28262c

https://git.kernel.org/stable/c/a8f5d39971bbad9340d49cd41b0e2da9452a649d

https://git.kernel.org/stable/c/52a56cf53ec834c44ac1b4d16d585f26613ee5ce

https://git.kernel.org/stable/c/2b4592cea214683de0f2ce6f8c22c097fb0ea1ab

Details

Source: Mitre, NVD

Published: 2026-07-25

Updated: 2026-08-11

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

EPSS

EPSS: 0.00209