CVE-2026-24669: Open eClass Auth Bypass Vulnerability

CVE-2026-24669 Overview

The Open eClass platform (formerly known as GUnet eClass) is a complete course management system used by educational institutions. Prior to version 4.2, an insecure password reset mechanism allows local attackers to reuse a valid password reset token after it has already been used, enabling unauthorized password changes and potential account takeover. This vulnerability is classified under CWE-613 (Insufficient Session Expiration).

Critical Impact

This vulnerability enables attackers with local access to perform account takeover by reusing password reset tokens that should have been invalidated after their first use, potentially compromising any user account in the Open eClass system.

Affected Products

• Open eClass (GUnet eClass) versions prior to 4.2
• Open eClass course management system

Discovery Timeline

• February 3, 2026 - CVE-2026-24669 published to NVD
• February 4, 2026 - Last updated in NVD database

Technical Details for CVE-2026-24669

Vulnerability Analysis

This vulnerability stems from improper session management in the password reset functionality of Open eClass. The platform fails to properly invalidate password reset tokens after their initial use, creating a window of opportunity for attackers. When a legitimate user initiates a password reset and uses the token to change their password, the token remains valid in the system. An attacker with local access to the same machine or network could intercept or retrieve this token and reuse it to change the victim's password again, effectively taking over the account.

The attack requires local access and user interaction, but the impact is severe as it affects the confidentiality, integrity, and availability of user accounts.

Root Cause

The root cause of this vulnerability is CWE-613: Insufficient Session Expiration. The password reset mechanism does not implement proper token lifecycle management. Specifically, the system fails to:

1. Invalidate tokens immediately upon successful use
2. Implement single-use token enforcement
3. Properly track token consumption state in the database

This design flaw allows tokens to persist in a valid state beyond their intended single-use lifecycle.

Attack Vector

The attack vector is local (AV:L), requiring the attacker to have access to the local system or network where the password reset process occurs. The attack unfolds as follows:

1. A legitimate user requests a password reset, receiving a token via email
2. The user successfully uses the token to reset their password
3. An attacker with local access captures or retrieves the used token from browser history, network traffic, or system logs
4. The attacker submits the same token to the password reset endpoint
5. Due to the vulnerability, the system accepts the reused token
6. The attacker changes the password, gaining unauthorized access to the victim's account

For detailed technical information, refer to the GitHub Security Advisory.

Detection Methods for CVE-2026-24669

Indicators of Compromise

• Multiple password reset completions using the same token within server logs
• Anomalous password change events for user accounts without corresponding user-initiated requests
• Repeated access to password reset confirmation endpoints with identical token parameters
• User reports of unexpected password changes or account lockouts

Detection Strategies

• Monitor authentication logs for multiple successful password resets from the same token
• Implement alerting on password change events that occur after a recent password change for the same account
• Analyze web server access logs for repeated POST requests to password reset endpoints with identical token values
• Cross-reference password reset completions with legitimate user session activity

Monitoring Recommendations

• Enable detailed logging for all authentication and password management functions
• Configure alerts for duplicate token usage patterns in password reset workflows
• Implement user notification mechanisms for all password change events
• Review access logs regularly for signs of token replay attacks

How to Mitigate CVE-2026-24669

Immediate Actions Required

• Upgrade Open eClass to version 4.2 or later immediately
• Audit recent password reset logs for signs of token reuse exploitation
• Force password resets for any accounts showing suspicious activity
• Review and revoke any active sessions for potentially compromised accounts
• Notify users of affected systems about the vulnerability and remediation steps

Patch Information

The vulnerability has been patched in Open eClass version 4.2. Organizations running earlier versions should upgrade immediately. The patch implements proper token invalidation after first use, ensuring password reset tokens cannot be reused. For patch details, see the GitHub Security Advisory.

Workarounds

• Restrict local access to systems where Open eClass is accessed to trusted users only
• Implement network segmentation to limit exposure of password reset traffic
• Configure browser security policies to prevent caching of sensitive URLs
• Educate users to clear browser history after completing password resets
• Monitor for suspicious password reset activity until the patch can be applied

# Verify Open eClass version and upgrade
# Check current version in Open eClass admin panel
# Download and apply version 4.2 or later from official repository
cd /var/www/openeclass
git fetch origin
git checkout v4.2
# Follow official upgrade documentation for database migrations