Warpgate Kubernetes listener leaks errors to unauthenticated callers
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-209.
Summary
Warpgate before 0.29.0 has a Kubernetes protocol listener that accepts any client certificate at the TLS layer and defers validation to later code. Authentication and lookup failures are returned verbatim in HTTP 500 response bodies, a case of CWE-209 (error messages containing sensitive information). An unauthenticated network client can trigger these failures and receive ASN.1/DER parser diagnostics or database errors, and the attempts are not recorded in the gateway log. The disclosed information is limited to internal diagnostics, with no user-data, integrity or availability impact established.
Written with Claude Haiku 5.5 from the sources below · 2026-11-04
Description from the CNA
Warpgate is an open source SSH, HTTPS, and MySQL bastion host for Linux. Prior to 0.29.0, the Kubernetes protocol listener uses AcceptAnyClientCert in warpgate-protocol-kubernetes/src/server/client_certs.rs to accept certificates at the TLS layer and defer validation to warpgate-protocol-kubernetes/src/server/auth.rs, where authentication and lookup failures are rendered verbatim in an HTTP 500 response body. The Kubernetes application in warpgate-protocol-kubernetes/src/server/mod.rs lacks the outer request-logging wrapper used by the HTTP protocol, and failures in warpgate-protocol-kubernetes/src/server/handlers.rs can short-circuit before its inner log point. An unauthenticated network client can therefore induce failures and receive ASN.1/DER parser diagnostics or sea_orm database errors without the attempt being recorded in the gateway log. The disclosed information is limited to internal diagnostics, and no user-data, integrity, or availability impact is established. This issue is fixed in version 0.29.0.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Update warp-tech warpgate to version 0.29.0, which fixes the issue.
Written with Claude Haiku 5.5 from the sources below · 2026-11-04
- Fix · CNA warpgate (warp-tech) Fixed in 0.29.0
Timeline
- 2026-11-04 Threatist record created from CVE-2026-91163
References
More warp-tech vulnerabilities
- TI-2023-18898 User login confusion with SSO in warpgate CVSS 3.1HIGH 8.8
- TI-2026-30510 Russh: Pre-auth DoS via unbounded allocation in keyboard-interactive auth CVSS 3.1HIGH 7.5
- TI-2024-29059 Russh has an OOM Denial of Service due to allocation of untrusted amount CVSS 3.1HIGH 7.5
- TI-2026-45163 Improper authorization in warp-tech warpgate CVSS 3.1HIGH 7.7
- TI-2026-32313 Warpgate: SSO CSRF -- State Token Not Validated on Return CVSS 3.1MEDIUM 6.5
- TI-2025-34558 Russh is missing an overflow check during channel windows adjust CVSS 3.1MEDIUM 6.5
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences