CVE-2026-49445: 
Cilium vulnerability analysis and mitigation

CVE-2026-49445 is a vulnerability in Cilium — a networking, observability, and security solution for Kubernetes — where the Envoy instance creates a world-accessible Unix domain socket (admin.sock) on cluster nodes when L7 functionality is enabled. This allows a local attacker to access Envoy admin endpoints without any credentials. Affected versions include all Cilium releases prior to 1.17.14, versions 1.18.0–1.18.7, and versions 1.19.0–1.19.1. The vulnerability was published on July 6, 2026, and carries a CVSS v3.1 base score of 9.2 (Critical) per the GitHub Security Advisory, or 8.8 (High) per NVD scoring (GitHub Advisory, Feedly).

The root cause is incorrect permission assignment for a critical resource (CWE-732) combined with missing authorization controls (CWE-862): the Envoy admin socket at /var/run/cilium/envoy/sockets/admin.sock was created without an explicit file mode, defaulting to world-accessible permissions (mode 0666 or similar) rather than the intended restricted mode 0660. The fix, implemented in PR #44512, explicitly sets mode: 0660 on the socket for both embedded and standalone Envoy deployment models — in install/kubernetes/cilium/files/cilium-envoy/configmap/bootstrap-config.yaml and pkg/envoy/embedded_envoy.go (GitHub PR, GitHub Commit). Exploitation requires only local access to a cluster node with low privileges, and no user interaction is needed (GitHub Advisory).

A local attacker with access to a cluster node can interact with the Envoy admin API via the world-readable socket, enabling exposure of TLS secrets (confidentiality impact), disruption of cluster traffic routing (integrity impact), and termination of the Envoy process (availability impact). Because the scope is changed — the vulnerable component (Cilium/Envoy) can affect resources beyond its own security boundary — the blast radius extends to the broader Kubernetes cluster, potentially enabling lateral movement or interception of service mesh traffic (GitHub Advisory, Feedly).

No public proof-of-concept exploit code is known to exist, and there is no evidence of in-the-wild exploitation at this time (Feedly). The NVD SSVC assessment classifies exploitation as "none" and the vulnerability as non-automatable. The EPSS score is approximately 0.0017 (0.17%), indicating a low probability of exploitation in the near term. The vulnerability is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, though it was referenced in a CISA bulletin (Feedly).

1. Gain local node access: Obtain a shell on a Kubernetes cluster node running a vulnerable Cilium version (prior to 1.17.14, 1.18.8, or 1.19.2) with L7 policy enforcement enabled — for example, via a compromised pod with host path access or direct node SSH access.
2. Locate the admin socket: Identify the Envoy admin socket at /var/run/cilium/envoy/sockets/admin.sock and confirm it is world-accessible using ls -la /var/run/cilium/envoy/sockets/.
3. Interact with Envoy admin API: Use a tool such as curl with the --unix-socket flag to communicate with the admin endpoint, e.g., curl --unix-socket /var/run/cilium/envoy/sockets/admin.sock http://localhost/.
4. Extract TLS secrets: Query the /certs or /config_dump admin endpoints to retrieve TLS certificate and key material used by Envoy for mTLS or L7 inspection.
5. Disrupt cluster traffic or terminate Envoy: Issue admin commands such as POST /quitquitquit to terminate the Envoy process, causing L7 policy enforcement to fail open or drop traffic, or manipulate routing configuration to disrupt service mesh communication (GitHub Advisory, GitHub PR).

• File System: Presence of /var/run/cilium/envoy/sockets/admin.sock with world-readable/writable permissions (mode 0666 or 0777) on unpatched nodes; verify with stat /var/run/cilium/envoy/sockets/admin.sock.
• Process/Logs: Unexpected or unauthorized processes (e.g., curl, socat, nc) accessing the Envoy admin socket; audit logs showing access to /var/run/cilium/envoy/sockets/admin.sock by non-Cilium processes.
• Network: Sudden termination or restart of the Envoy process on cluster nodes, which may indicate a quitquitquit admin call was issued; unexpected changes in L7 traffic routing or policy enforcement failures.
• Logs: Envoy admin access log entries (if enabled) showing requests to sensitive endpoints such as /config_dump, /certs, /clusters, or /quitquitquit from unexpected sources.

Upgrade Cilium to one of the patched versions: 1.17.14, 1.18.8, or 1.19.2, which explicitly set the admin socket permissions to mode 0660, restricting access to the socket owner and group only (GitHub Release v1.17.14, GitHub Release v1.18.8). The Cilium security advisory states there is no known workaround for this issue (GitHub Advisory). As a compensating control until patching is possible, restrict local access to cluster nodes through host-level access controls, node hardening, and limiting which users or pods can access the host filesystem (Feedly). Note that GKE users on v1.18.8 should upgrade directly to v1.19.2 due to a known regression in that release.

The vulnerability was reported by community member "moemen" and triaged and remediated by Cilium contributor "0xch4z" (Charlie Kenney), with acknowledgment from the Cilium/Isovalent security team (GitHub Advisory). The Hacker Wire published a dedicated write-up on the issue shortly after public disclosure (The Hacker Wire). The vulnerability was also referenced in a CISA weekly vulnerability bulletin, indicating it received attention from government cybersecurity bodies (Feedly).