Attack Chain

1. An attacker first gains local access to a Kubernetes cluster node where Cilium is deployed.
2. The node is running a vulnerable version of Cilium with L7 functionality enabled, causing an Envoy proxy instance to be deployed.
3. The Envoy instance, due to the misconfiguration, creates a world-accessible Unix domain socket for its administration interface.
4. The local attacker discovers and accesses this world-accessible Envoy admin socket.
5. The attacker then leverages the accessible admin endpoints to query for sensitive configuration data, such as TLS secrets.
6. Alternatively, the attacker utilizes the admin endpoints to issue commands that disrupt network traffic within the cluster.
7. The attacker might also terminate the Envoy process, leading to a denial of service for L7-managed traffic.
8. The final objective is either information exfiltration (e.g., TLS secrets) or denial of service to cluster resources.

Impact

This vulnerability poses a critical threat to the confidentiality and availability of Kubernetes clusters using Cilium with L7 functionality. Exploitation by a local attacker can directly lead to the exposure of highly sensitive information, such as TLS private keys, which could then be used for decrypting network communications, impersonating services, or escalating privileges. Beyond data theft, the attacker can disrupt or completely halt network traffic managed by Envoy, causing a denial of service for critical applications and services running within the cluster. Terminating the Envoy process directly impacts service availability. All deployment models, including embedded and standalone Envoy, are affected, increasing the potential blast radius across diverse Cilium installations. The source does not provide specific victim counts but highlights significant consequences for any affected organization.

Recommendation

• Immediately upgrade all affected Cilium installations to a patched version (v1.19.2, v1.18.8, or v1.17.14) to remediate CVE-2026-49445.
• Implement robust host-level security measures to prevent unauthorized local access to Kubernetes cluster nodes, thereby mitigating the prerequisite for this local exploitation.