Vulnerability in Linux

CVE-2025-21826

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: reject mismatching sum of field_len with set key length The field length description provides the length of each separated key field in the concatenation, each field gets rounded up to 32-bits to calculate the pipapo rule width from pipapo_init(). The set key length provides the total size of the key aligned to 32-bits. Register-based arithmetics still allows for combining mismatching set key length and field length description, eg. set key length 10 and field description [ 5, 4 ] leading to pipapo width of 12.

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: 0.002 (8.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 8.9% 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-2025-21826: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

  • Linux — versions 5.10.209, 3ce67e3793f48c1b9635beb9bb71116ca1e51b58, 77be8c495a3f841e88b46508cc20d3d7d3289da3
  • Linux Kernel

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-21826?
CVE-2025-21826 is a high-severity vulnerability in Linux. CVSS score: 7.8/10. Published 2025-03-06.
How severe is CVE-2025-21826?
High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2025-21826 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.