{"id":"CVE-2026-61682","aliases":["GHSA-c8w2-fgvx-vhv4"],"url":"https://o3.security/vulnerability/CVE-2026-61682","summary":"kcp front-proxy does not strip inbound X-Remote-* identity headers, allowing any authenticated client to inject groups/warrants and impersonate system:masters in any workspace","details":"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.","published":"2026-09-18T16:11:46.443Z","modified":"2026-09-19T03:47:22.462715160Z","cvss":{"score":9.9,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Go","name":"github.com/kcp-dev/kcp","fixedVersion":"0.31.4"},{"ecosystem":"Go","name":"github.com/kcp-dev/kcp","fixedVersion":"0.32.2"}],"fix":{"url":"https://github.com/kcp-dev/kcp/commit/7437cdcfec8f927d1a9bf1b2dd1e075d038e27ca","label":"kcp-dev/kcp@7437cdc"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61682.json"},{"type":"FIX","url":"https://github.com/kcp-dev/kcp/commit/7437cdcfec8f927d1a9bf1b2dd1e075d038e27ca"},{"type":"FIX","url":"https://github.com/kcp-dev/kcp/commit/f913ee890fb2fd9fa78e50c43474b078bfb6aeff"},{"type":"WEB","url":"https://github.com/kcp-dev/kcp/releases/tag/v0.31.4"},{"type":"WEB","url":"https://github.com/kcp-dev/kcp/releases/tag/v0.32.2"},{"type":"ADVISORY","url":"https://github.com/kcp-dev/kcp/security/advisories/GHSA-c8w2-fgvx-vhv4"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-61682"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-19T03:47:22.462715160Z"}}