The dataplane token validator in kuma-cp performs an unchecked Go type assertion on the JWT kid header. A token whose kid is a JSON number decodes as a float64 and triggers a runtime panic before any signature, claims, or authorization check runs.
The panic terminates the entire kuma-cp process, HTTP API, the health and readiness endpoints, and xDS. Unauthenticated access to the dataplane gRPC server can trigger the crash with a malformed token
A single request is a transient interruption; sustaining an outage requires repeated requests.
You are affected if any control plane has its dataplane (xDS) gRPC server reachable by an untrusted party.
You are not affected if the dataplane server is reachable only by trusted data planes on an isolated network.
Restrict network access to the dataplane (xDS) gRPC port to trusted data planes.
Upgrade to Kong Mesh 2.7.29, 2.9.19, 2.11.18, 2.12.14, 2.13.10 or 2.14.2, whichever matches your release line. In patched versions the validator rejects a non-string kid header and the dataplane server recovers from handler panics.