Cilium East-west traffic not subject to egress policy enforcement for requests via Gateway API load balancers
### Impact For Cilium users who: - Use Gateway API for Ingress for some services **AND** - Use [LB-IPAM](https://docs.cilium.io/en/stable/network/lb-ipam/) or BGP for LB Service implementation **AND** - Use network policies to block egress traffic from workloads in a namespace to workloads in other namespaces Egress traffic from workloads covered by such network policies to LoadBalancers configured by `Gateway` resources will incorrectly be allowed. LoadBalancer resources not deployed via a Gateway API configuration are not affected by this issue. ### Patches This issue was fixed by https://github.com/cilium/proxy/pull/1172. This issue affects: - Cilium v1.15 between v1.15.0 and v1.15.14 inclusive - Cilium v1.16 between v1.16.0 and v1.16.7 inclusive - Cilium v1.17 between v1.17.0 and v1.17.1 inclusive This issue is fixed in: - Cilium v1.15.15 - Cilium v1.16.8 - Cilium v1.17.2 ### Workarounds A Clusterwide Cilium Network Policy can be used to work around this issue for users who are unable to upgrade. An outline of such a policy is provided below: ``` apiVersion: "cilium.io/v2" kind: CiliumClusterwideNetworkPolicy metadata: name: "workaround" spec: endpointSelector: matchExpressions: - key: reserved:ingress operator: Exists ingress: - fromEntities: - world ``` - The policy opens up connectivity from all locations outside the cluster into the Cilium Ingress Gateway. - The policy establishes a default deny for all other traffic towards the Cilium Ingress Gateway, including all in-cluster sources. - It is possible to tailor the policy to more narrowly allow inbound traffic while creating a default deny posture for traffic between namespaces. Users should edit the policy to bring it in line with the security requirements particular to their environments. ### Acknowledgements The Cilium community has worked together with members of the Isovalent team to prepare these mitigations. Special thanks to @jrajahalme for the fix. ### For more information If you think you have found a vulnerability affecting Cilium, we strongly encourage you to report it to our security mailing list at [[email protected]](mailto:[email protected]). This is a private mailing list for the Cilium security team, and your report will be treated as top priority.
02 / AFFECTED SOFTWARE
Affected packages
50 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
Cilium East-west traffic not subject to egress policy enforcement for requests via Gateway API load balancers in github.com/cilium/cilium
### Impact For Cilium users who: - Use Gateway API for Ingress for some services **AND** - Use [LB-IPAM](https://docs.cilium.io/en/stable/network/lb-ipam/) or BGP for LB Service implementation **AND** - Use network policies to block egress traffic from workloads in a namespace to workloads in other namespaces Egress traffic from workloads covered by such network policies to LoadBalancers configured by `Gateway` resources will incorrectly be allowed. LoadBalancer resources not deployed via a Gateway API configuration are not affected by this issue. ### Patches This issue was fixed by https://github.com/cilium/proxy/pull/1172. This issue affects: - Cilium v1.15 between v1.15.0 and v1.15.14 inclusive - Cilium v1.16 between v1.16.0 and v1.16.7 inclusive - Cilium v1.17 between v1.17.0 and v1.17.1 inclusive This issue is fixed in: - Cilium v1.15.15 - Cilium v1.16.8 - Cilium v1.17.2 ### Workarounds A Clusterwide Cilium Network Policy can be used to work around this issue for users who are unable to upgrade. An outline of such a policy is provided below: ``` apiVersion: "cilium.io/v2" kind: CiliumClusterwideNetworkPolicy metadata: name: "workaround" spec: endpointSelector: matchExpressions: - key: reserved:ingress operator: Exists ingress: - fromEntities: - world ``` - The policy opens up connectivity from all locations outside the cluster into the Cilium Ingress Gateway. - The policy establishes a default deny for all other traffic towards the Cilium Ingress Gateway, including all in-cluster sources. - It is possible to tailor the policy to more narrowly allow inbound traffic while creating a default deny posture for traffic between namespaces. Users should edit the policy to bring it in line with the security requirements particular to their environments. ### Acknowledgements The Cilium community has worked together with members of the Isovalent team to prepare these mitigations. Special thanks to @jrajahalme for the fix. ### For more information If you think you have found a vulnerability affecting Cilium, we strongly encourage you to report it to our security mailing list at [[email protected]](mailto:[email protected]). This is a private mailing list for the Cilium security team, and your report will be treated as top priority.
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. For Cilium users who use Gateway API for Ingress for some services and use LB-IPAM or BGP for LB Service implementation and use network policies to block egress traffic from workloads in a namespace to workloads in other namespaces, egress traffic from workloads covered by such network policies to LoadBalancers configured by `Gateway` resources will incorrectly be allowed. LoadBalancer resources not deployed via a Gateway API configuration are not affected by this issue. This issue affects: Cilium v1.15 between v1.15.0 and v1.15.14 inclusive, v1.16 between v1.16.0 and v1.16.7 inclusive, and v1.17 between v1.17.0 and v1.17.1 inclusive. This issue is fixed in Cilium v1.15.15, v1.16.8, and v1.17.2. A Clusterwide Cilium Network Policy can be used to work around this issue for users who are unable to upgrade.
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. For Cilium users who use Gateway API for Ingress for some services and use LB-IPAM or BGP for LB Service implementation and use network policies to block egress traffic from workloads in a namespace to workloads in other namespaces, egress traffic from workloads covered by such network policies to LoadBalancers configured by `Gateway` resources will incorrectly be allowed. LoadBalancer resources not deployed via a Gateway API configuration are not affected by this issue. This issue affects: Cilium v1.15 between v1.15.0 and v1.15.14 inclusive, v1.16 between v1.16.0 and v1.16.7 inclusive, and v1.17 between v1.17.0 and v1.17.1 inclusive. This issue is fixed in Cilium v1.15.15, v1.16.8, and v1.17.2. A Clusterwide Cilium Network Policy can be used to work around this issue for users who are unable to upgrade.
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. For Cilium users who use Gateway API for Ingress for some services and use LB-IPAM or BGP for LB Service implementation and use network policies to block egress traffic from workloads in a namespace to workloads in other namespaces, egress traffic from workloads covered by such network policies to LoadBalancers configured by `Gateway` resources will incorrectly be allowed. LoadBalancer resources not deployed via a Gateway API configuration are not affected by this issue. This issue affects: Cilium v1.15 between v1.15.0 and v1.15.14 inclusive, v1.16 between v1.16.0 and v1.16.7 inclusive, and v1.17 between v1.17.0 and v1.17.1 inclusive. This issue is fixed in Cilium v1.15.15, v1.16.8, and v1.17.2. A Clusterwide Cilium Network Policy can be used to work around this issue for users who are unable to upgrade.
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. For Cilium users who use Gateway API for Ingress for some services and use LB-IPAM or BGP for LB Service implementation and use network policies to block egress traffic from workloads in a namespace to workloads in other namespaces, egress traffic from workloads covered by such network policies to LoadBalancers configured by `Gateway` resources will incorrectly be allowed. LoadBalancer resources not deployed via a Gateway API configuration are not affected by this issue. This issue affects: Cilium v1.15 between v1.15.0 and v1.15.14 inclusive, v1.16 between v1.16.0 and v1.16.7 inclusive, and v1.17 between v1.17.0 and v1.17.1 inclusive. This issue is fixed in Cilium v1.15.15, v1.16.8, and v1.17.2. A Clusterwide Cilium Network Policy can be used to work around this issue for users who are unable to upgrade.
05 / REFERENCES
Further evidence
- https://docs.cilium.io/en/stable/network/lb-ipam
- https://github.com/cilium/cilium/security/advisories/GHSA-24qp-4xx8-3jvj
- https://github.com/cilium/proxy/pull/1172
- https://nvd.nist.gov/vuln/detail/CVE-2025-30162
- https://github.com/cilium/cilium
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/30xxx/CVE-2025-30162.json