CVE-2026-56742 Cilium: Namespaced HTTPRoutes can redirect traffic to other namespaces
Attackers with HTTPRoute permissions can bypass ReferenceGrant to mirror traffic to services in other namespaces, exposing sensitive data.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-56742?
CVE-2026-56742 is a medium-severity missing authorization vulnerability in cilium, published on 15 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-862
Which versions are affected by CVE-2026-56742?
10 open source packages ship an affected version, including github.com/cilium/cilium, cilium and cilium-operator. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/cilium/cilium Go | All versions | 1.17.17, 1.18.11, 1.19.5 |
github.com/cilium/cilium Go | All versions | 1.17.17 |
github.com/cilium/cilium Go | All versions | 1.17.17 |
github.com/cilium/cilium Go | From 1.19.0 | 1.19.5 |
github.com/cilium/cilium Go | From 1.19.0 | 1.19.5 |
cilium Bitnami | All versions | 1.17.17, 1.18.11, 1.19.5 |
4 more packages
cilium-operator Bitnami | All versions | 1.17.17, 1.18.11, 1.19.5 |
hubble-relay Bitnami | All versions | 1.17.17, 1.18.11, 1.19.5 |
github.com/cilium/ciliumCilium Go | From 1.18.0 | 1.18.11 |
github.com/cilium/ciliumCilium Go | From 1.18.0 | 1.18.11 |
Products include Cilium Cilium.
How do I fix CVE-2026-56742?
Upgrade github.com/cilium/cilium to a fixed version for your release line: 1.17.17, 1.18.11 or 1.19.5.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-56742 being exploited?
There is no known exploitation of CVE-2026-56742 in the wild and no public exploit code.
Other vulnerabilities in cilium
- CVE-2026-49445 Cilium: Sensitive information disclosure and cluster disruption via local Envoy admin socket access
- CVE-2022-29178 Incorrect Default Permissions in Cilium
- CVE-2024-28860 Insecure IPsec transport encryption in Cilium
- CVE-2026-41520 Cillium exposes sensitive information included in the cilium-bugtool debug archive
- CVE-2024-37307 Cilium leaks sensitive information in cilium-bugtool
Sources
Also known as BIT-cilium-2026-56742, BIT-cilium-operator-2026-56742, BIT-hubble-relay-2026-56742, GHSA-w7c2-w76w-5hmj, GO-2026-6596, MINI-44cf-6rxq-c8rp and 27 more.