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)
- 0.4%
- Status
- patched
- Published
Is CVE-2026-61682 being exploited?
Not on any exploited-vulnerability catalog we track. CVE-2026-61682 was not on the CISA, ENISA or CIRCL exploited catalogs as of our 2026-11-04 snapshot. That can change quickly; check the write-up below for the latest reporting.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 0.4% (scored October 14, 2026).
- CISA KEV[ — ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-11-04. Full cross-catalog view: /kev-comparison
CVE-2026-61682 timeline
Every event links to its source. Catalog dates are each catalog's own; day offsets count from NVD publication. Data: JSON
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.
