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.

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Fixes

Solution

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.


Workaround

Restrict network access to the dataplane (xDS) gRPC port to trusted data planes.

History

Wed, 12 Aug 2026 19:00:00 +0000

Type Values Removed Values Added
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.
Title Kong Mesh: control plane denial of service via a malformed dataplane token with a non-string JWT kid
Weaknesses CWE-248
CWE-704
References
Metrics cvssV4_0

{'score': 5.3, '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'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Kong

Published:

Updated: 2026-08-12T18:36:17.377Z

Reserved: 2026-08-03T15:20:42.168Z

Link: CVE-2026-18675

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-12T19:17:30.650

Modified: 2026-08-12T19:17:30.650

Link: CVE-2026-18675

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses