CVE-2026-26963

Cilium may not enforce host firewall policies when Native Routing, WireGuard and Node Encryption are enabled

State: Published
Severity: 6.1 Medium
Published: Feb 19, 2026
Updated: Feb 20, 2026
Reserved: Feb 16, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	6.1 Medium	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N	GitHub_M

Weaknesses

CWE-863 Incorrect Authorization

Affected Products

Product	Versions
ciliumcilium	>= 1.18.0, < 1.18.6Affected

References

https://github.com/cilium/cilium/security/advisories/GHSA-5r23-prx4-mqg3
https://github.com/cilium/cilium/pull/42892
https://github.com/cilium/cilium/commit/88e28e1e62c0b1a02c3f0fc22d888ac9eefbe885
https://github.com/cilium/cilium/releases/tag/v1.18.6

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