Description
Cilium is a networking, observability, and security solution. Prior to 1.17.17, 1.18.11, and 1.19.5, Cilium clusters using Gateway API allow users with permissions to create or update namespaced HTTPRoutes to mirror HTTP traffic to any Service in any namespace, bypassing the ReferenceGrant authorization mechanism. Gateway API functionality is disabled by default. This issue is fixed in versions 1.17.17, 1.18.11, and 1.19.5.
Affected products
cilium: cilium
References8
- github.com/cilium/cilium/security/advisories/GHSA-w7c2-w76w-5hmj Vendor Advisory
- github.com/cilium/cilium/commit/7422068aff67ac77c7dcc57aa5b9240… Patch
- github.com/cilium/cilium/commit/e0b1cef513ff910323f3743e9f3e3d8… Patch
- github.com/cilium/cilium/commit/f23929cff682d6ed0dc158070812cb3… Patch
- github.com/cilium/cilium/commit/fd47963ea394d5e8fa4a88c40a79063… Patch
- github.com/cilium/cilium/releases/tag/v1.17.17 Release Notes
- github.com/cilium/cilium/releases/tag/v1.18.11 Release Notes
- github.com/cilium/cilium/releases/tag/v1.19.5 Release Notes
Metrics
- CVSS 3.1
-
8.9
HIGH
Score source: NVD
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L - EPSS — exploit probability
- 0% percentile: 7 · as of 15 November 2026
- CWE
- CWE-862
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.