CVE-2025-40285

In the Linux kernel, the following vulnerability has been resolved: smb/server: fix possible refcount leak in smb2_sess_setup() Reference count of ksmbd_session will leak when session need reconnect. Fix this by adding the missing ksmbd_user_session_put().

Package Linux Kernel
Published 2025-12-06
Last modified 2026-04-15
Patch available
Yes

Affected versions

Linux kernel versions 6.1.121, 6.6.67, 6.12.6, 5.15.176, 6.13 and later are affected. Fixed in 6.1.159, 6.6.117, 6.12.59, 6.17.9, 6.18 and their respective stable series.

Affected from
≥ 6.1.121 ≥ 6.6.67 ≥ 6.12.6 ≥ 5.15.176 ≥ 6.13
Fixed in
✓ 6.1.159 6.1.x ✓ 6.6.117 6.6.x ✓ 6.12.59 6.12.x ✓ 6.17.9 6.17.x ✓ 6.18

References

The following references provide additional information about CVE-2025-40285 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Frequently asked questions

  • What is CVE-2025-40285?

    CVE-2025-40285 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.1.121 onward and has been patched in 6.1.159, 6.6.117, 6.12.59 and others. CVE-2025-40285 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • Is there a patch available for CVE-2025-40285?

    Yes — CVE-2025-40285 has been patched. Fixed versions include 6.1.159, 6.6.117, 6.12.59 and others. If you are running Linux kernel 6.1.121 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2025-40285 actively exploited?

    No — CVE-2025-40285 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.