Compliance Impact

This vulnerability allows an attacker with a valid session token to take over a user's two-factor authentication (2FA) without any verification, effectively compromising the integrity of the authentication process.

Such a compromise can lead to unauthorized access to user accounts, which may result in exposure or misuse of personal or sensitive data.

Consequently, this vulnerability could negatively impact compliance with standards and regulations like GDPR and HIPAA, which require strong access controls and protection of personal and sensitive information.

Useful 0 Not Useful 0

Executive Summary

CVE-2026-54036 is a vulnerability in LibreChat versions 0.8.3-rc1 and earlier that allows an attacker with a valid session token to fully take over a user's two-factor authentication (2FA) without any OTP verification.

The issue lies in the /api/auth/2fa/enable endpoint, which can be called even when 2FA is already enabled. This endpoint overwrites the existing TOTP secret, generates new backup codes, and disables 2FA without requiring any re-verification of the user's identity.

An attacker exploiting this vulnerability can replace the victim's 2FA secret with their own, invalidate all existing backup codes, disable 2FA, and then re-enable 2FA under their control, effectively locking the legitimate user out of their own two-factor authentication.

Useful 0 Not Useful 0

Impact Analysis

This vulnerability allows an attacker who has obtained a valid session token to completely take over your two-factor authentication (2FA) mechanism.

By exploiting this flaw, the attacker can disable your existing 2FA, replace your authentication secrets, and lock you out of your own account's 2FA protections.

This means that even if you have 2FA enabled, an attacker with a stolen session can bypass it and gain unauthorized access to your account, compromising your account's security and integrity.

Useful 0 Not Useful 0

Detection Guidance

This vulnerability can be detected by monitoring for unauthorized calls to the /api/auth/2fa/enable endpoint from authenticated sessions, especially if 2FA is already enabled on the account.

Network or application logs should be inspected for suspicious POST or GET requests to this endpoint that result in changes to 2FA settings without proper verification.

Suggested commands include using tools like curl or HTTP request log analysis to detect such calls. For example, checking web server logs with grep:

• grep "/api/auth/2fa/enable" /var/log/nginx/access.log
• grep "/api/auth/2fa/enable" /var/log/apache2/access.log

Additionally, monitoring session tokens usage and looking for unusual activity patterns or multiple 2FA resets can help detect exploitation.

Useful 0 Not Useful 0

Mitigation Strategies

The immediate mitigation step is to upgrade LibreChat to version 0.8.4-rc1 or later, where this vulnerability is fixed.

Until the upgrade is applied, restrict access to the /api/auth/2fa/enable endpoint to prevent unauthorized calls, for example by implementing stricter authentication checks or network-level access controls.

Additionally, monitor for suspicious activity related to 2FA changes and consider invalidating all active sessions to prevent attackers with stolen tokens from exploiting the vulnerability.

Useful 0 Not Useful 0