Grav CMS 2FA Bypass Vulnerability Disclosed in Login Plugin

Grav CMS versions prior to 2.0.4 are affected by a critical two-factor authentication (2FA) bypass vulnerability tracked as CVE-2026-62232. This flaw resides within the platform's login plugin and permits unauthorized users to overwrite 2FA secrets, allowing them to bypass secondary authentication requirements entirely.

What's at Risk

The vulnerability affects all deployments of Grav CMS running versions earlier than 2.0.4. Organizations utilizing the login plugin for user authentication are at significant risk, particularly those with internet-facing administrative panels. Because the flaw allows for the manipulation of security settings without proper authorization, any system relying on 2FA as a primary defense against unauthorized access is currently exposed.

How the Flaw Works

This vulnerability is categorized as an authentication bypass, a class of weakness that typically occurs when a system fails to properly verify the identity or authorization level of a user before performing sensitive operations. In general terms, flaws of this nature allow an attacker to circumvent security controls by exploiting logical oversights in the code, such as failing to check if a user possesses the necessary permissions to execute a specific task. When an application assumes a user is authorized simply because they exist or have reached a certain stage in a workflow, it opens the door for attackers to manipulate system states, escalate privileges, or disable security features like multi-factor authentication.

How to Protect Your Systems

• Update Grav CMS immediately to version 2.0.4 or later to patch the vulnerable login plugin.
• Audit user accounts for any suspicious changes to 2FA settings or unexpected login activity.
• Restrict access to administrative interfaces by implementing IP whitelisting or VPN requirements.
• Enforce strong password policies to mitigate the risk of attackers gaining initial access, which is a prerequisite for this exploit.
• Monitor server logs for unauthorized attempts to access sensitive tasks or configuration endpoints.

The CVSS 7.4 severity rating underscores the importance of addressing this flaw immediately. By failing to authenticate the requestor during the TOTP challenge window, the system inadvertently grants an attacker the ability to reduce 2FA to password-only protection. Promptly applying the vendor-provided patch is the most effective way to secure your environment against this bypass and ensure that multi-factor authentication remains a robust barrier against unauthorized access.