CVE-2026-61682: CWE-290: Authentication Bypass by Spoofing in kcp-dev kcp
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.
AI Analysis
Technical Summary
The kcp front-proxy in affected versions fails to strip inbound identity headers such as X-Remote-User, X-Remote-Group, and X-Remote-Extra-* before forwarding requests to shards. Because shards trust these headers as authenticated identity assertions, an authenticated tenant can inject headers like X-Remote-Group: system:masters or other privileged groups, enabling cross-workspace impersonation and authorization bypass. This flaw allows attackers to read, write, or delete critical resources including secrets, RBAC configurations, APIExports, APIBindings, and LogicalClusters. The vulnerability is addressed by removing these headers in versions 0.31.4 and 0.32.2.
Potential Impact
Successful exploitation allows an authenticated tenant to bypass authorization controls by spoofing identity headers, leading to cross-workspace impersonation and full access to sensitive resources. This includes the ability to read, modify, or delete secrets, RBAC data, APIExports, APIBindings, and LogicalClusters, severely compromising confidentiality, integrity, and availability within the kcp environment.
Mitigation Recommendations
Upgrade to kcp versions 0.31.4 or 0.32.2 or later, where the front-proxy properly removes inbound X-Remote-User, X-Remote-Group, and X-Remote-Extra-* headers before forwarding requests. No other mitigations are indicated by the vendor advisory. Patch status is confirmed fixed in these versions.
CVE-2026-61682: CWE-290: Authentication Bypass by Spoofing in kcp-dev kcp
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.
CVSS v3.1
Score 9.9critical
Affected software
kcp-dev
kcp
pkg:github/kcp-dev/kcpRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The kcp front-proxy in affected versions fails to strip inbound identity headers such as X-Remote-User, X-Remote-Group, and X-Remote-Extra-* before forwarding requests to shards. Because shards trust these headers as authenticated identity assertions, an authenticated tenant can inject headers like X-Remote-Group: system:masters or other privileged groups, enabling cross-workspace impersonation and authorization bypass. This flaw allows attackers to read, write, or delete critical resources including secrets, RBAC configurations, APIExports, APIBindings, and LogicalClusters. The vulnerability is addressed by removing these headers in versions 0.31.4 and 0.32.2.
Potential Impact
Successful exploitation allows an authenticated tenant to bypass authorization controls by spoofing identity headers, leading to cross-workspace impersonation and full access to sensitive resources. This includes the ability to read, modify, or delete secrets, RBAC data, APIExports, APIBindings, and LogicalClusters, severely compromising confidentiality, integrity, and availability within the kcp environment.
Mitigation Recommendations
Upgrade to kcp versions 0.31.4 or 0.32.2 or later, where the front-proxy properly removes inbound X-Remote-User, X-Remote-Group, and X-Remote-Extra-* headers before forwarding requests. No other mitigations are indicated by the vendor advisory. Patch status is confirmed fixed in these versions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-07-10T18:36:58.848Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6aad640855bf5e2cf53a6a48
Added to database: 09/18/2026, 16:17:12 UTC
Last enriched: 09/18/2026, 16:31:41 UTC
Last updated: 09/18/2026, 23:38:13 UTC
Views: 12
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