6.1

CVE-2026-26963: Cilium may not enforce host firewall policies when Native Routing, WireGuard and Node Encryption are enabled

Analyzed
AliasesUBUNTU-CVE-2026-26963GHSA-5r23-prx4-mqg3BIT-cilium-2026-26963
Published 19-02-2026Last modified 20-02-2026

Vulnerability summary

CVE-2026-26963 is a medium (CVSS 6.1) Incorrect Authorization vulnerability in cilium. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 7.4% of scored vulnerabilities.

Overall risk
24/100
0100
Low · default modelHow is this calculated?
CVSS score
6.1/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.18%
0%100%
Low · +0.05 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2 · Related 2
OPENSUSE-SU-2026:21483-1SUSE-SU-2026:0757-1

Timeline

  1. 19-02-2026
    PublishedVulnerability first disclosed.
  2. 20-02-2026
    Last modifiedVulnerability information updated.

Description

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Versions 1.18.0 through 1.18.5 will incorrectly permit traffic from Pods on other nodes when Native Routing, WireGuard and Node Encryption are enabled. This issue has been fixed in version 1.18.6.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.18%

Chance of exploitation in the next 30 days

Percentile

7%

Versus all other CVEs

30-day change

Increase +0.05 pp

From 0.13% on 22-09-2026

22-09-202622-10-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Cilium1 product
Github.com/cilium1 product
  • cilium≥ 1.18.0, < 1.18.6
Ubuntu1 product
  • golang-github-cilium-ebpfAll versions (No fix recorded)

3 vendors · 3 products

References

8 links