CVE-2026-63329

Warpgate: x-warpgate-username Header Not Stripped from Client Requests Enables Identity Spoofing to WebSocket Backend Targets

MEDIUM
4.9
CVSS Score
Published: September 21, 2026 at 06:49 PM UTC
Updated: September 24, 2026 at 09:37 PM UTC
1 product affected across 1 vendorWarpgate

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Severity
MEDIUM4.9
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.25.6
Affected range stops below 0.25.6, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.9MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-116CWE-290

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