CVE-2026-31717

High

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).

Package Linux Kernel
Published 2026-05-01
Last modified 2026-06-01
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

8.8

out of 10
High
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected versions

Linux kernel versions 6.6.32, 6.9 and later are affected. Fixed in 6.6.142, 6.12.92, 6.18.25, 7.0.2, 7.1-rc1 and their respective stable series.

Affected from
≥ 6.6.32 ≥ 6.9
Fixed in
✓ 6.6.142 6.6.x ✓ 6.12.92 6.12.x ✓ 6.18.25 6.18.x ✓ 7.0.2 7.0.x ✓ 7.1-rc1

References

The following references provide additional information about CVE-2026-31717 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

5 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2026-31717?

    CVE-2026-31717 is a High severity Linux kernel vulnerability with a CVSS score of 8.8 out of 10 . It affects Linux kernel versions from 6.6.32 onward and has been patched in 6.6.142, 6.12.92, 6.18.25 and others. CVE-2026-31717 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-31717?

    CVE-2026-31717 has a CVSS score of 8.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H .

  • Is there a patch available for CVE-2026-31717?

    Yes — CVE-2026-31717 has been patched. Fixed versions include 6.6.142, 6.12.92, 6.18.25 and others. If you are running Linux kernel 6.6.32 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-31717 actively exploited?

    No — CVE-2026-31717 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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