CVE-2026-64391ksmbd: use opener credentials for ADS I/O
- 9.8CriticalCVSS base score
- 0.49%Exploitation in 30 daysEPSS · top 57% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By Linux
- 6 days later
· 6 days later
Published
- 3 months later
· 3 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.49% · top 57% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
- affected f44158485826c076335d6860d35872271a83791d – < 222c4c52c3af2d0f68de31182710df3508a31095
- affected f44158485826c076335d6860d35872271a83791d – < 2ad5509dd576ae16d252d4698daf03002f9e0234
- affected f44158485826c076335d6860d35872271a83791d – < a8f5d39971bbad9340d49cd41b0e2da9452a649d
- affected f44158485826c076335d6860d35872271a83791d – < 2b4592cea214683de0f2ce6f8c22c097fb0ea1ab
- affected f44158485826c076335d6860d35872271a83791d – < 52a56cf53ec834c44ac1b4d16d585f26613ee5ce
- affected f44158485826c076335d6860d35872271a83791d – < baa5e094886fffa7e6272edcb5e08be5ce28262c
- affected 5.15
- unaffected < 5.15
- unaffected 6.1.191 – ≤ 6.1.*
- unaffected 6.6.160 – ≤ 6.6.*
- unaffected 6.12.96 – ≤ 6.12.*
- unaffected 6.18.39 – ≤ 6.18.*
- unaffected 7.1.4 – ≤ 7.1.*
- unaffected 7.2 – ≤ *
References
References6
- https://git.kernel.org/stable/c/222c4c52c3af2d0f68de31182710df3508a31095 (opens in a new tab)
- https://git.kernel.org/stable/c/2ad5509dd576ae16d252d4698daf03002f9e0234 (opens in a new tab)
- https://git.kernel.org/stable/c/a8f5d39971bbad9340d49cd41b0e2da9452a649d (opens in a new tab)
- https://git.kernel.org/stable/c/2b4592cea214683de0f2ce6f8c22c097fb0ea1ab (opens in a new tab)
- https://git.kernel.org/stable/c/52a56cf53ec834c44ac1b4d16d585f26613ee5ce (opens in a new tab)
- https://git.kernel.org/stable/c/baa5e094886fffa7e6272edcb5e08be5ce28262c (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-48935 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-64391)Record last updated .