Use After Free in Linux

CVE-2025-21945

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in smb2_lock If smb_lock->zero_len has value, ->llist of smb_lock is not delete and flock is old one. It will cause use-after-free on error handling routine.

Vulnerability class: Use-After-Free

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (41.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 41.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-21945: held from 0.005 to 0.005.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: +0.000

Affected products

  • Linux — versions 0626e6641f6b467447c81dd7678a69c66f7746cf, 5.15, 0
  • Linux Kernel — versions 6.14

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-21945?
CVE-2025-21945 is a high-severity vulnerability in Linux, classified under Use After Free. CVSS score: 8.8/10. Published 2025-04-01.
How severe is CVE-2025-21945?
High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2025-21945 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.