CVE-2026-39429: Kcp

Critical severity, CVSS 9.1. EPSS: 0.5% chance of exploitation in the next 30 days.

kcp is a Kubernetes-like control plane for form-factors and use-cases beyond Kubernetes and container workloads. Prior to 0.30.3 and 0.29.3, the cache server is directly exposed by the root shard and has no authentication or authorization in place. This allows anyone who can access the root shard to read and write to the cache server. This vulnerability is fixed in 0.30.3 and 0.29.3.

Affected products

• Kcp Kcp: before 0.29.3 (fixed in 0.29.3); from 0.30.0, before 0.30.3 (fixed in 0.30.3)

Published 2026-04-08. Last modified 2026-07-24.