Use After Free in Linux

CVE-2025-21791

In the Linux kernel, the following vulnerability has been resolved: vrf: use RCU protection in l3mdev_l3_out() l3mdev_l3_out() can be called without RCU being held: raw_sendmsg() ip_push_pending_frames() ip_send_skb() ip_local_out() __ip_local_out() l3mdev_ip_out() Add rcu_read_lock() / rcu_read_unlock() pair to avoid a potential UAF.

Vulnerability class: Use-After-Free

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.003 (17.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 17th percentile — 17.2% 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-2025-21791: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000

Affected products

  • Linux — versions a8e3e1a9f02094145580ea7920c6a1d9aabd5539, 4.9, 0
  • Linux Kernel — versions 6.14

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-21791?
CVE-2025-21791 is a high-severity vulnerability in Linux, classified under Use After Free. CVSS score: 7.8/10. Published 2025-02-27.
How severe is CVE-2025-21791?
High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2025-21791 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.