Vulnerability 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.
Related Weaknesses (CWE)
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
FAQ
What is CVE-2026-18675?
CVE-2026-18675 is a documented vulnerability. 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 ...
How severe is CVE-2026-18675?
CVSS scoring is not yet available for CVE-2026-18675. Check NVD for updates.
Is there a patch for CVE-2026-18675?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.