Vulnerability in Linux

CVE-2025-21766

In the Linux kernel, the following vulnerability has been resolved: ipv4: use RCU protection in __ip_rt_update_pmtu() __ip_rt_update_pmtu() must use RCU protection to make sure the net structure it reads does not disappear.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (43.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 43.5% 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-2025-21766: 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 6.13.4, 98776a365da509ad923083ae54b38ee521c52742, 5.4.68
  • Linux Kernel — versions 5.9, 6.14

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-21766?
CVE-2025-21766 is a high-severity vulnerability in Linux. CVSS score: 8.1/10. Published 2025-02-27.
How severe is CVE-2025-21766?
High severity. CVSS v3 base score is 8.1 out of 10.
Is CVE-2025-21766 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.