CVE-2026-61682
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
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Critical9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
| NVDNVD · Deferred | 3.1 | Critical9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.38% · top 67% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.9.
Weakness
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Gogithub.com/kcp-dev/kcpGHSA-c8w2-fgvx-vhv4 (opens in a new tab)
References (5)
- https://github.com/kcp-dev/kcp/security/advisories/GHSA-c8w2-fgvx-vhv4 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/kcp-dev/kcp/commit/7437cdcfec8f927d1a9bf1b2dd1e075d038e27ca (opens in a new tab)x_refsource_MISC
- https://github.com/kcp-dev/kcp/commit/f913ee890fb2fd9fa78e50c43474b078bfb6aeff (opens in a new tab)x_refsource_MISC
- https://github.com/kcp-dev/kcp/releases/tag/v0.31.4 (opens in a new tab)x_refsource_MISC
- https://github.com/kcp-dev/kcp/releases/tag/v0.32.2 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-c8w2-fgvx-vhv4 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-61682)Record last updated .