Cilium is a networking, observability, and security solution with an eBPF-based dataplane. An insecure default `Access-Control-Allow-Origin` header value could lead to sensitive data exposure for users of Cilium versions 1.14.0 through 1.14.7, 1.15.0 through 1.15.11, and 1.16.0 through 1.16.4 who deploy Hubble UI using either Cilium CLI or via the Cilium Helm chart. A user with access to a Hubble UI instance affected by this issue could leak configuration details about the Kubernetes cluster which Hubble UI is monitoring, including node names, IP addresses, and other metadata about workloads and the cluster networking configuration. In order for this vulnerability to be exploited, a victim would have to first visit a malicious page. This issue is fixed in Cilium v1.14.18, v1.15.12, and v1.16.5. As a workaround, users who deploy Hubble UI using the Cilium Helm chart directly can remove the CORS headers from the Helm template as shown in the patch from commit a3489f190ba6e87b5336ee685fb…

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. A denial of service vulnerability affects versions 1.14.0 through 1.14.7, 1.15.0 through 1.15.11, and 1.16.0 through 1.16.4. In a Kubernetes cluster where Cilium is configured to proxy DNS traffic, an attacker can crash Cilium agents by sending a crafted DNS response to workloads from outside the cluster. For traffic that is allowed but without using DNS-based policy, the dataplane will continue to pass traffic as configured at the time of the DoS. For workloads that have DNS-based policy configured, existing connections may continue to operate, and new connections made without relying on DNS resolution may continue to be established, but new connections which rely on DNS resolution may be disrupted. Any configuration changes that affect the impacted agent may not be applied until the agent is able to restart. This issue is fixed in Cilium v1.14.18, v1.15.12, and v1.16.5. No known workarounds ar…

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. For users with the following configuration: 1. An allow policy that selects a Layer 3 destination and a port range `AND` 2. A Layer 7 allow policy that selects a specific port within the first policy's range the Layer 7 enforcement would not occur for the traffic selected by the Layer 7 policy. This issue only affects users who use Cilium's port range functionality, which was introduced in Cilium v1.16. This issue is patched in PR #35150. This issue affects Cilium v1.16 between v1.16.0 and v1.16.3 inclusive. This issue is patched in Cilium v1.16.4. Users are advised to upgrade. Users with network policies that match the pattern described above can work around the issue by rewriting any policies that use port ranges to individually specify the ports permitted for traffic.

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Starting in version 1.14.0 and prior to versions 1.14.16 and 1.15.10, a policy rule denying a prefix that is broader than `/32` may be ignored if there is a policy rule referencing a more narrow prefix (`CIDRSet` or `toFQDN`) and this narrower policy rule specifies either `enableDefaultDeny: false` or `- toEntities: all`. Note that a rule specifying `toEntities: world` or `toEntities: 0.0.0.0/0` is insufficient, it must be to entity `all`.This issue has been patched in Cilium v1.14.16 and v1.15.10. As this issue only affects policies using `enableDefaultDeny: false` or that set `toEntities` to `all`, some workarounds are available. For users with policies using `enableDefaultDeny: false`, remove this configuration option and explicitly define any allow rules required. For users with egress policies that explicitly specify `toEntities: all`, use `toEntities: world`.

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. In versions on the 1.15.x branch prior to 1.15.8 and the 1.16.x branch prior to 1.16.1, ReferenceGrant changes are not correctly propagated in Cilium's GatewayAPI controller, which could lead to Gateway resources being able to access secrets for longer than intended, or to Routes having the ability to forward traffic to backends in other namespaces for longer than intended. This issue has been patched in Cilium v1.15.8 and v1.16.1. As a workaround, any modification of a related Gateway/HTTPRoute/GRPCRoute/TCPRoute CRD (for example, adding any label to any of these resources) will trigger a reconciliation of ReferenceGrants on an affected cluster.

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Prior to versions 1.14.14 and 1.15.8, a race condition in the Cilium agent can cause the agent to ignore labels that should be applied to a node. This could in turn cause CiliumClusterwideNetworkPolicies intended for nodes with the ignored label to not apply, leading to policy bypass. This issue has been patched in Cilium v1.14.14 and v1.15.8 As the underlying issue depends on a race condition, users unable to upgrade can restart the Cilium agent on affected nodes until the affected policies are confirmed to be working as expected.

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. In the 1.15 branch prior to 1.15.8 and the 1.16 branch prior to 1.16.1, Gateway API HTTPRoutes and GRPCRoutes do not follow the match precedence specified in the Gateway API specification. In particular, request headers are matched before request methods, when the specification describes that the request methods must be respected before headers are matched. This could result in unexpected behaviour with security This issue is fixed in Cilium v1.15.8 and v1.16.1. There is no workaround for this issue.

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Starting in version 1.13.0 and prior to versions 1.13.7, 1.14.12, and 1.15.6, the output of `cilium-bugtool` can contain sensitive data when the tool is run (with the `--envoy-dump` flag set) against Cilium deployments with the Envoy proxy enabled. Users of the TLS inspection, Ingress with TLS termination, Gateway API with TLS termination, and Kafka network policies with API key filtering features are affected. The sensitive data includes the CA certificate, certificate chain, and private key used by Cilium HTTP Network Policies, and when using Ingress/Gateway API and the API keys used in Kafka-related network policy. `cilium-bugtool` is a debugging tool that is typically invoked manually and does not run during the normal operation of a Cilium cluster. This issue has been patched in Cilium v1.15.6, v1.14.12, and v1.13.17. There is no workaround to this issue.

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Users of IPsec transparent encryption in Cilium may be vulnerable to cryptographic attacks that render the transparent encryption ineffective. In particular, Cilium is vulnerable to chosen plaintext, key recovery, replay attacks by a man-in-the-middle attacker. These attacks are possible due to an ESP sequence number collision when multiple nodes are configured with the same key. Fixed versions of Cilium use unique keys for each IPsec tunnel established between nodes, resolving all of the above attacks. This vulnerability is fixed in 1.13.13, 1.14.9, and 1.15.3.

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Starting in version 1.14.0 and prior to versions 1.14.8 and 1.15.2, In Cilium clusters with WireGuard enabled and traffic matching Layer 7 policies Wireguard-eligible traffic that is sent between a node's Envoy proxy and pods on other nodes is sent unencrypted and Wireguard-eligible traffic that is sent between a node's DNS proxy and pods on other nodes is sent unencrypted. This issue has been resolved in Cilium 1.14.8 and 1.15.2 in in native routing mode (`routingMode=native`) and in Cilium 1.14.4 in tunneling mode (`routingMode=tunnel`). Not that in tunneling mode, `encryption.wireguard.encapsulate` must be set to `true`. There is no known workaround for this issue.