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

EPSS: 0.003 (18.2th percentile) — read the EPSS interpretation.

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.

Affected products

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.