CVE-2026-31717
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate owner of durable handle on reconnect Currently, ksmbd does not verify if the user attempting to reconnect to a durable handle is the same user who originally opened the file. This allows any authenticated user to hijack an orphaned durable handle by predicting or brute-forcing the persistent ID. According to MS-SMB2, the server MUST verify that the SecurityContext of the reconnect request matches the SecurityContext associated with the existing open. Add a durable_owner structure to ksmbd_file to store the original opener's UID, GID, and account name. and catpure the owner information when a file handle becomes orphaned. and implementing ksmbd_vfs_compare_durable_owner() to validate the identity of the requester during SMB2_CREATE (DHnC).
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
Linux kernel Affected 2 releases
| Version | Status | Fixed in |
|---|---|---|
| 7.1 | Affected | — |
| — | Affected | 6.7 |
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Windows Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Debian Mixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Affected | — |
| sid | Fixed | 7.0.3-1 |
| forky | Fixed | 7.0.3-1 |
| bullseye | Fixed | 0 |
| bookworm | Fixed | 0 |
References
- https://git.kernel.org/stable/c/00ce8d6789dae72d042a4522264964c72891ca37
- https://git.kernel.org/stable/c/49110a8ce654bbe56bef7c5e44cce31f4b102b8a
- https://git.kernel.org/stable/c/c908c853f304a4969b5aa10eba0b50350cc65b80
- https://www.suse.com/security/cve/CVE-2026-31717.html
- https://security-tracker.debian.org/tracker/CVE-2026-31717
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-31717
- https://git.kernel.org/stable/c/712cdf917e77a6444ce3836874829d770db20ee6
- https://git.kernel.org/stable/c/c7f0f0d01c88bdcb8b1694d7d321670013f7ed7d
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.