Cilium: Security Vulnerabilities
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.
CVSS Score
5.9
EPSS Score
0.002
Published
2026-07-15
Cilium is a networking, observability, and security solution. From 1.19.0 to 1.19.4, standard Kubernetes NetworkPolicy specifications using CIDR-based ipBlock rules without pod or namespace selectors erroneously generate a wildcard namespace allow rule when Cilium is configured with a custom clusterName rather than the default any value. The parser incorrectly instantiates a pod selector on selectorless peer definitions, allowing traffic from other workloads in the same namespace as the subject of the policy. This issue is fixed in version 1.19.5.
CVSS Score
5.4
EPSS Score
0.002
Published
2026-07-15
Cilium is a networking, observability, and security solution. Prior to 1.17.14, 1.18.8, and 1.19.2, when Cilium L7 functionality is enabled, the embedded or standalone Envoy instance creates a world-accessible admin.sock on cluster nodes, allowing a local attacker to access Envoy admin endpoints, expose TLS secrets, disrupt cluster traffic, or terminate Envoy. This issue is fixed in versions 1.17.14, 1.18.8, and 1.19.2.
CVSS Score
9.2
EPSS Score
0.001
Published
2026-07-15
A vulnerability has been found in cilium ebpf up to 0.21.0. This affects the function loadRawSpec of the file btf/btf.go of the component LoadCollectionSpec/LoadCollectionSpecFromReader. Such manipulation of the argument offset leads to integer overflow. The attack can only be performed from a local environment. The exploit has been disclosed to the public and may be used. The name of the patch is 533dfc82fd228bfadf42ea7180c39de7d9af47fa. A patch should be applied to remediate this issue.
CVSS Score
1.9
EPSS Score
0.002
Published
2026-06-03
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Prior to versions 1.17.15, 1.18.9, and 1.19.3, the output of cilium-bugtool can contain sensitive data when the tool is run against Cilium deployments with WireGuard encryption enabled. This issue has been patched in versions 1.17.15, 1.18.9, and 1.19.3.
CVSS Score
7.9
EPSS Score
0.001
Published
2026-05-08
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Prior to versions 1.17.14, 1.18.8, and 1.19.2, Ingress Network Policies are not enforced for traffic from pods to L7 Services (Envoy, GAMMA) with a local backend on the same node, when Per-Endpoint Routing is enabled and BPF Host Routing is disabled. Per-Endpoint Routing is disabled by default, but is automatically enabled in deployments using cloud IPAM, including Cilium ENI on EKS (`eni.enabled`), AlibabaCloud ENI (`alibabacloud.enabled`), Azure IPAM (`azure.enabled`, but not AKS BYOCNI), and some GKE deployments (`gke.enabled`; managed offerings such as GKE Dataplane V2 may use different defaults). It is typically not enabled in tunneled deployments, and chaining deployments are not affected. In practice, Amazon EKS with Cilium ENI mode is likely the most common affected environment. Versions 1.17.14, 1.18.8, and 1.19.2 contain a patch. There is currently no officially verified or comprehensive workaround for this issue. The only option would be to disable per-endpoint routes, but this will likely cause disruptions to ongoing connections, and potential conflicts if running in cloud providers.
CVSS Score
5.4
EPSS Score
0.002
Published
2026-03-27
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 Score
6.1
EPSS Score
0.001
Published
2026-02-20
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Prior to versions 1.16.17, 1.17.10, and 1.18.4, CiliumNetworkPolicys which use egress.toGroups.aws.securityGroupsIds to reference AWS security group IDs that do not exist or are not attached to any network interface may unintentionally allow broader outbound access than intended by the policy authors. In such cases, the toCIDRset section of the derived policy is not generated, which means outbound traffic may be permitted to more destinations than originally intended. This issue has been patched in versions 1.16.17, 1.17.10, and 1.18.4. There are no workarounds for this issue.
CVSS Score
4.0
EPSS Score
0.002
Published
2025-11-29
Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Versions 1.15.0 to 1.15.15, 1.16.0 to 1.16.8, and 1.17.0 to 1.17.2, are vulnerable when using Wireguard transparent encryption in a Cilium cluster, packets that originate from a terminating endpoint can leave the source node without encryption due to a race condition in how traffic is processed by Cilium. This issue has been patched in versions 1.15.16, 1.16.9, and 1.17.3. There are no workarounds available for this issue.
CVSS Score
4.0
EPSS Score
0.001
Published
2025-04-21
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.
CVSS Score
3.2
EPSS Score
0.002
Published
2025-03-24
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