Review reviewHigh

CVE-2025-40328

Linux

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.

CVSS: 8.8
EPSS: 0.40%
CISA KEV: Not listed
Published: 2025.12.10

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.40%

Technical severityCVSS 8.8

Vulnerability overview

Affected product and versions

Product: Linux
Affected versions: >= ebe98f1447bbccf8228335c62d86af02a0ed23f7 < cb52d9c86d70298de0ab7c7953653898cbc0efd6, >= ebe98f1447bbccf8228335c62d86af02a0ed23f7 < 065bd62412271a2d734810dd50336cae88c54427, >= ebe98f1447bbccf8228335c62d86af02a0ed23f7 < bdb596ceb4b7c3f28786a33840263728217fbcf5, >= ebe98f1447bbccf8228335c62d86af02a0ed23f7 < 734e99623c5b65bf2c03e35978a0b980ebc3c2f8, >= 6.1
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that Linux and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CWE: Not available