CVE-2026-18675

Description

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.

References

• https://developer.konghq.com/mesh/changelog/
• https://github.com/kumahq/kuma/pull/17465
• https://github.com/kumahq/kuma/pull/17467
• https://github.com/kumahq/kuma/pull/17468
• https://github.com/kumahq/kuma/pull/17469
• https://github.com/kumahq/kuma/pull/17470
• https://github.com/kumahq/kuma/pull/17471
• https://github.com/kumahq/kuma/pull/17472
• https://github.com/kumahq/kuma/security/advisories/GHSA-5mxq-7xq4-3vx8