CVE Record
[ CRITICAL ]CVE-2026-61682
kcp front-proxy passes X-Remote-User headers without stripping, enables user impersonation
kcp front-proxy before 0.31.4 and 0.32.2 does not remove inbound X-Remote-User headers, letting unauthenticated callers impersonate any user. CVSS 9.9 critical.
- Vendor
- kcp-dev
- Product
- kcp
- CVSS
- 9.9
- EPSS (exploit probability)
- 0.3%
- Status
- patched
- Published
kcp is a Kubernetes-like control plane. Prior to versions 0.31.4 and 0.32.2, the kcp front-proxy does not strip inbound X-Remote-User and related impersonation headers. A caller who can reach the front-proxy can set those headers to any value and be authenticated as that user, including cluster administrators.
Fixed in kcp 0.31.4 and 0.32.2. No workaround is documented; the fix removes the unsafe header pass-through.
See NVD and the kcp GitHub advisory for full version details.
