CVE-2026-63329
Received Received - Intake

HTTP Header Injection in Warpgate

Publication date: 2026-09-21

Last updated on: 2026-09-21

Assigner: GitHub, Inc.

Description
Warpgate is an open source SSH, HTTPS and MySQL bastion host for Linux. Prior to 0.25.6, copy_server_request in warpgate-protocol-http/src/proxy.rs forwards a client-supplied x-warpgate-username header before inject_own_headers appends the authenticated username. Because the request builder preserves repeated values, a proxied backend that trusts the first x-warpgate-username value can authorize an authenticated attacker as another user. The same forwarding policy also accepts the reserved x-warpgate-authentication-type header, and warpgate-common/src/http_headers.rs does not exclude either reserved identity header. This issue is fixed in version 0.25.6.

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Meta Information

Published
2026-09-21
Last Modified
2026-09-21
Generated
2026-09-22
AI Q&A
2026-09-21
EPSS Evaluated
N/A
NVD
CVE-2026-63329
EUVD
EUVD-2026-84060

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
warpgate warpgate to 0.25.6 (exc)
warp_tech warpgate to 0.25.6 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-116 The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.
CWE-290 This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.

Attack-Flow Graph

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Executive Summary

CVE-2026-63329 is a security flaw in Warpgate versions before 0.25.6. It involves the HTTP/WebSocket proxy forwarding client-supplied headers like x-warpgate-username and x-warpgate-authentication-type to backend servers without stripping them. Attackers can inject forged headers with a victim's username before Warpgate appends the real one. Backends that trust the first header value may authorize the attacker as the victim, leading to unauthorized access.

Detection Guidance

To detect this vulnerability, check if your Warpgate version is prior to 0.25.6. Run: warpgate --version. Inspect HTTP/WebSocket traffic for forwarded x-warpgate-username or x-warpgate-authentication-type headers. Use tools like tcpdump or Wireshark to capture and analyze headers in requests.

Impact Analysis

If you use Warpgate as a bastion host for SSH, HTTPS, or MySQL, an authenticated attacker could impersonate another user by injecting a forged x-warpgate-username header. This could lead to unauthorized access to sensitive systems, data breaches, or account takeovers, especially if backend services rely on this header for authentication.

Compliance Impact

This vulnerability could lead to unauthorized access to personal or sensitive data, violating compliance requirements under GDPR and HIPAA. GDPR requires protecting personal data, while HIPAA mandates safeguarding protected health information. A breach could result in legal penalties, reputational damage, and loss of trust.

Mitigation Strategies

Upgrade Warpgate to version 0.25.6 or later immediately. Review and update backend services to ignore x-warpgate-username and x-warpgate-authentication-type headers. Monitor network traffic for suspicious header forwarding patterns.

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