CVE-2026-18675

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.

Scoring

Severity
MEDIUM
CVSS base score
5.3
CVSS vector
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
EPSS probability
0.38%
CWE
CWE-248, CWE-704
Published
2026-08-12
Last modified
2026-08-13

Affected products

Weakness type

Related vulnerabilities

Markdown version · Browse all CVEs