{"id":"CVE-2026-61682","state":"PUBLISHED","title":"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","description":"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.","publishedAt":"2026-09-18T16:11:46.443Z","updatedAt":"2026-09-21T20:50:17.494Z","severity":{"score":9.9,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["kcp-dev kcp"],"affected":[{"vendor":"kcp-dev","product":"kcp","versions":[{"version":"< 0.31.4","status":"affected"},{"version":">= 0.32.0, < 0.32.2","status":"affected"}]}],"references":["https://github.com/kcp-dev/kcp/security/advisories/GHSA-c8w2-fgvx-vhv4","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"],"weaknesses":["CWE-290","CWE-302","CWE-348"],"ingestedAt":"2026-10-29T20:12:32.778Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/61xxx/CVE-2026-61682.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-61682","state":"PUBLISHED","datePublished":"2026-09-18T16:11:46.443Z","dateUpdated":"2026-09-21T20:50:17.494Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-07-10T18:36:58.848Z"},"containers":{"cna":{"title":"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","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"kcp-dev","product":"kcp","versions":[{"version":"< 0.31.4","status":"affected"},{"version":">= 0.32.0, < 0.32.2","status":"affected"}]}],"references":[{"url":"https://github.com/kcp-dev/kcp/security/advisories/GHSA-c8w2-fgvx-vhv4","name":"https://github.com/kcp-dev/kcp/security/advisories/GHSA-c8w2-fgvx-vhv4","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/kcp-dev/kcp/commit/7437cdcfec8f927d1a9bf1b2dd1e075d038e27ca","name":"https://github.com/kcp-dev/kcp/commit/7437cdcfec8f927d1a9bf1b2dd1e075d038e27ca","tags":["x_refsource_MISC"]},{"url":"https://github.com/kcp-dev/kcp/commit/f913ee890fb2fd9fa78e50c43474b078bfb6aeff","name":"https://github.com/kcp-dev/kcp/commit/f913ee890fb2fd9fa78e50c43474b078bfb6aeff","tags":["x_refsource_MISC"]},{"url":"https://github.com/kcp-dev/kcp/releases/tag/v0.31.4","name":"https://github.com/kcp-dev/kcp/releases/tag/v0.31.4","tags":["x_refsource_MISC"]},{"url":"https://github.com/kcp-dev/kcp/releases/tag/v0.32.2","name":"https://github.com/kcp-dev/kcp/releases/tag/v0.32.2","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":9.9,"baseSeverity":"CRITICAL","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-290","lang":"en","description":"CWE-290: Authentication Bypass by Spoofing","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-302","lang":"en","description":"CWE-302: Authentication Bypass by Assumed-Immutable Data","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-348","lang":"en","description":"CWE-348: Use of Less Trusted Source","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-18T16:11:46.443Z"},"source":{"advisory":"GHSA-c8w2-fgvx-vhv4","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-18T19:24:33.782681Z","id":"CVE-2026-61682","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-21T20:50:17.494Z"}}]}}}