CVE-2026-64391
Published: July 29, 2026Last modified: November 3, 2026
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 9.8 |
| Attack Vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Fixed (6.1.191-r0) |
| 25 LTS | linux-lts | Fixed (6.12.103-r0) | |
| Stream | linux-lts | Fixed (6.18.43-r0) |
References
- https://git.kernel.org/stable/c/222c4c52c3af2d0f68de31182710df3508a31095
- https://git.kernel.org/stable/c/2ad5509dd576ae16d252d4698daf03002f9e0234
- 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