CVE-2026-44347: Warpgate SSO Auth Bypass Vulnerability

CVE-2026-44347 Overview

CVE-2026-44347 affects Warpgate, an open source SSH, HTTPS, and MySQL bastion host for Linux. Versions prior to 0.23.3 fail to validate the state parameter during the Single Sign-On (SSO) authentication flow. An attacker can exploit this gap to perform a login Cross-Site Request Forgery (CSRF) attack [CWE-352]. The attacker tricks a victim into authenticating as the attacker, then induces them to perform sensitive actions on the attacker-controlled account. The vulnerability is fixed in Warpgate version 0.23.3.

Critical Impact
A successful attack can cause a victim to write sensitive data to an attacker-controlled SSH target or interact with an attacker-controlled HTTP target, exposing credentials and confidential data.

Affected Products

Warpgate versions prior to 0.23.3
Confirmed affected build: warpgate 0.23.2
Warpgate SSO authentication flow (SSH, HTTPS, and MySQL bastion components)

Discovery Timeline

2026-05-12 - CVE-2026-44347 published to NVD
2026-05-14 - Last updated in NVD database

Technical Details for CVE-2026-44347

Vulnerability Analysis

Warpgate acts as a bastion host that brokers access to internal SSH, HTTPS, and MySQL targets. The platform supports SSO providers for user authentication. During the SSO authorization code flow, the client should generate a unique, unpredictable state value, bind it to the user session, and verify it when the identity provider redirects back with the authorization code.

Warpgate releases prior to 0.23.3 skip the state verification step. An attacker initiates an SSO login, captures the resulting redirect URL containing the authorization code, and delivers that URL to a victim. When the victim visits the link, Warpgate completes the SSO exchange and binds the attacker's identity to the victim's browser session.

The victim, believing they are logged into their own account, may then write files to SSH targets, paste credentials into HTTP applications, or execute queries against MySQL targets — all under the attacker's identity. The attacker later logs into the same account and retrieves the data.

Root Cause

The root cause is missing CSRF protection in the SSO callback handler. The implementation does not generate or verify the OAuth 2.0 state parameter, violating the OAuth 2.0 specification's session-binding requirement.

Attack Vector

Exploitation is network-based and requires user interaction. The attacker must initiate an SSO flow, intercept the callback URL, and convince a target user to click the crafted link, typically through phishing or a malicious page.

No authentication or special privileges are required to launch the attack. Verified Proof-of-Concept code is not publicly available, and the EPSS probability stands at 0.015%. Refer to the Warpgate GitHub Security Advisory GHSA-rj86-hm3r-c275 for vendor-provided technical details.

Detection Methods for CVE-2026-44347

Indicators of Compromise

SSO callback requests to Warpgate that lack a state query parameter or contain a state value not previously issued by the server.
Authentication events where the user account presented after SSO does not match the account expected for the originating browser session.
Unusual SSH file writes, HTTP form submissions, or MySQL queries shortly after an SSO login from a user who reports session anomalies.

Detection Strategies

Audit Warpgate authentication logs for SSO callback URLs and confirm each request carries a state value that the server issued and has not seen before.
Correlate identity provider logs with Warpgate session logs to detect mismatches between the initiating browser and the authenticated principal.
Hunt for sensitive target activity — credential entry, key uploads, configuration changes — that immediately follows an SSO login.

Monitoring Recommendations

Enable verbose authentication logging on Warpgate and forward events to a centralized SIEM for retention and correlation.
Alert on Warpgate processes running versions earlier than 0.23.3 discovered through software inventory or vulnerability scans.
Monitor outbound connections from Warpgate targets to unexpected SSH or HTTP destinations that may indicate attacker-controlled infrastructure.

How to Mitigate CVE-2026-44347

Immediate Actions Required

Upgrade all Warpgate deployments to version 0.23.3 or later, which restores state parameter validation in the SSO flow.
Invalidate active Warpgate sessions and force re-authentication after the upgrade to clear any sessions established under vulnerable code.
Notify Warpgate users about the risk of clicking unsolicited login links and reinforce phishing-awareness training.

Patch Information

The maintainers fixed the issue in Warpgate 0.23.3. The patch adds generation and verification of the OAuth 2.0 state parameter during the SSO authorization code exchange. See the Warpgate GitHub Security Advisory GHSA-rj86-hm3r-c275 for release details.

Workarounds

Temporarily disable SSO authentication in Warpgate and require local or certificate-based authentication until the upgrade is complete.
Restrict Warpgate web access to trusted networks or VPN ranges to limit exposure to phishing-delivered callback URLs.
Instruct users to log out of Warpgate immediately if they encounter unexpected account states after an SSO login.

bash

# Configuration example: verify installed Warpgate version and upgrade
warpgate --version

# Pull the fixed release container image
docker pull ghcr.io/warp-tech/warpgate:0.23.3

# Restart the service to load the patched binary
systemctl restart warpgate