CVE-2025-40328

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential UAF in smb2_close_cached_fid() find_or_create_cached_dir() could grab a new reference after kref_put() had seen the refcount drop to zero but before cfid_list_lock is acquired in smb2_close_cached_fid(), leading to use-after-free. Switch to kref_put_lock() so cfid_release() is called with cfid_list_lock held, closing that gap.

Package Linux Kernel
Published 2025-12-09
Last modified 2026-04-15
Patch available
Yes

Affected versions

Linux kernel versions 6.1 and later are affected. Fixed in 6.6.117, 6.12.58, 6.17.8, 6.18 and their respective stable series.

Affected from
≥ 6.1
Fixed in
✓ 6.6.117 6.6.x ✓ 6.12.58 6.12.x ✓ 6.17.8 6.17.x ✓ 6.18

References

The following references provide additional information about CVE-2025-40328 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-2025-40328?

    CVE-2025-40328 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.1 onward and has been patched in 6.6.117, 6.12.58, 6.17.8 and others. CVE-2025-40328 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • Is there a patch available for CVE-2025-40328?

    Yes — CVE-2025-40328 has been patched. Fixed versions include 6.6.117, 6.12.58, 6.17.8 and others. If you are running Linux kernel 6.1 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2025-40328 actively exploited?

    No — CVE-2025-40328 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.