CVE-2026-61682

kcp is a Kubernetes-like control plane for form-factors and use-cases beyond Kubernetes and container workloads. Prior to 0.31.4 and 0.32.2, the kcp front-proxy does not remove inbound X-Remote-User, X-Remote-Group, or X-Remote-Extra-* identity headers before forwarding requests to shards. Any authenticated tenant can inject X-Remote-Group: system:masters, authorization.kcp.io/warrant, authentication.kcp.io/scopes, or a group used for per-workspace required-group gating, and the shard trusts these values as authenticated identity assertions. This allows cross-workspace impersonation, authorization bypass, and arbitrary reading, writing, or deletion of resources, secrets, RBAC data, APIExports, APIBindings, and LogicalClusters. This issue is fixed in versions 0.31.4 and 0.32.2.

• https://github.com/kcp-dev/kcp/commit/7437cdcfec8f927d1a9bf1b2dd1e075d038e27ca
• https://github.com/kcp-dev/kcp/commit/f913ee890fb2fd9fa78e50c43474b078bfb6aeff
• https://github.com/kcp-dev/kcp/releases/tag/v0.31.4
• https://github.com/kcp-dev/kcp/releases/tag/v0.32.2
• https://github.com/kcp-dev/kcp/security/advisories/GHSA-c8w2-fgvx-vhv4