CVE-2026-64391
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.46%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.46% probability · 39th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
EPSS 0.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://git.kernel.org/stable/c/2ad5509dd576ae16d252d4698daf03002f9e0234
- 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
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.