CVE-2026-31476

High

In the Linux kernel, the following vulnerability has been resolved: ksmbd: do not expire session on binding failure When a multichannel session binding request fails (e.g. wrong password), the error path unconditionally sets sess->state = SMB2_SESSION_EXPIRED. However, during binding, sess points to the target session looked up via ksmbd_session_lookup_slowpath() -- which belongs to another connection's user. This allows a remote attacker to invalidate any active session by simply sending a binding request with a wrong password (DoS). Fix this by skipping session expiration when the failed request was a binding attempt, since the session does not belong to the current connection. The reference taken by ksmbd_session_lookup_slowpath() is still correctly released via ksmbd_user_session_put().

Package Linux Kernel
Published 2026-04-22
Last modified 2026-06-01
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

8.2

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

Affected versions

Linux kernel versions 5.15 and later are affected. Fixed in 5.15.209, 6.1.168, 6.6.131, 6.12.80, 6.18.21, 6.19.11, 7.0 and their respective stable series.

Affected from
≥ 5.15
Fixed in
✓ 5.15.209 5.15.x ✓ 6.1.168 6.1.x ✓ 6.6.131 6.6.x ✓ 6.12.80 6.12.x ✓ 6.18.21 6.18.x ✓ 6.19.11 6.19.x ✓ 7.0

References

The following references provide additional information about CVE-2026-31476 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

7 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2026-31476?

    CVE-2026-31476 is a High severity Linux kernel vulnerability with a CVSS score of 8.2 out of 10 . It affects Linux kernel versions from 5.15 onward and has been patched in 5.15.209, 6.1.168, 6.6.131 and others. CVE-2026-31476 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-31476?

    CVE-2026-31476 has a CVSS score of 8.2 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H .

  • Is there a patch available for CVE-2026-31476?

    Yes — CVE-2026-31476 has been patched. Fixed versions include 5.15.209, 6.1.168, 6.6.131 and others. If you are running Linux kernel 5.15 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-31476 actively exploited?

    No — CVE-2026-31476 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

Back to
All CVEs
View on
NVD / NIST