CVE-2026-2895: Funadmin Auth Bypass Vulnerability

CVE-2026-2895 Overview

A weak password recovery vulnerability has been discovered in FunAdmin, an open-source content management system, affecting versions up to and including 7.1.0-rc4. The vulnerability exists in the repass function within the file app/frontend/controller/Member.php. By manipulating the forget_code and vercode arguments, an attacker can exploit the flawed password recovery mechanism to potentially reset user passwords without proper authorization.

The attack can be performed remotely over the network, though the complexity is rated as high due to the specific conditions required for successful exploitation. A public exploit has been released, increasing the risk of active exploitation. The vendor was contacted early about this disclosure but did not respond.

Critical Impact

Attackers may be able to bypass password recovery verification mechanisms to gain unauthorized access to user accounts, potentially compromising the integrity of user credentials across the affected FunAdmin installations.

Affected Products

• FunAdmin versions up to 7.1.0-rc4
• FunAdmin 7.1.0-rc1
• FunAdmin 7.1.0-rc2
• FunAdmin 7.1.0-rc3
• FunAdmin 7.1.0-rc4

Discovery Timeline

• 2026-02-21 - CVE-2026-2895 published to NVD
• 2026-02-24 - Last updated in NVD database

Technical Details for CVE-2026-2895

Vulnerability Analysis

This vulnerability is classified as CWE-640: Weak Password Recovery Mechanism for Forgotten Password. The weakness occurs in the password reset functionality within the Member.php controller, specifically in the repass function that handles password recovery requests.

The vulnerable function fails to properly validate the forget_code and vercode parameters used during the password reset process. These parameters are intended to serve as verification tokens to ensure that only the legitimate account owner can reset their password. However, the implementation contains flaws that allow an attacker to manipulate these values to bypass the verification process.

While the attack complexity is considered high and exploitation is difficult, the public availability of exploit details increases the practical risk. Successful exploitation would allow an attacker to reset passwords for arbitrary user accounts without proper authorization, leading to account takeover scenarios.

Root Cause

The root cause of this vulnerability lies in insufficient validation of the password recovery tokens (forget_code and vercode) within the repass function. The application does not adequately verify that these tokens correspond to a legitimate password reset request initiated by the actual account owner. This weak verification mechanism allows attackers to forge or manipulate these parameters to bypass the intended security controls.

Attack Vector

The attack is network-accessible, meaning it can be exploited remotely without requiring local access to the target system. The attack flow involves:

1. An attacker identifies a FunAdmin installation running a vulnerable version
2. The attacker targets the password recovery endpoint at app/frontend/controller/Member.php
3. By crafting malicious values for the forget_code and vercode parameters, the attacker attempts to bypass verification
4. If successful, the attacker can reset the password for a target user account
5. The attacker gains unauthorized access using the newly set password

The vulnerability requires no authentication and no user interaction, though the high attack complexity means specific conditions must be met for successful exploitation. For detailed technical information, refer to the GitHub Issue Discussion and VulDB entry.

Detection Methods for CVE-2026-2895

Indicators of Compromise

• Unusual or repeated password reset requests targeting the /Member/repass endpoint
• Multiple password reset attempts for different user accounts from the same source IP
• Anomalous values in forget_code or vercode parameters that don't match expected token formats
• Successful password changes without corresponding legitimate email verification clicks

Detection Strategies

• Implement web application firewall (WAF) rules to monitor and alert on suspicious patterns in password reset requests
• Configure logging to capture all requests to the Member.php controller, particularly the repass function
• Set up anomaly detection for password reset request volumes that exceed normal baselines
• Monitor for login attempts immediately following password reset requests from different geographic locations

Monitoring Recommendations

• Enable detailed access logging for all authentication and password recovery endpoints
• Implement rate limiting on the password recovery functionality to detect and prevent brute-force attempts
• Set up alerts for multiple failed or suspicious password reset attempts within a short time window
• Correlate password reset events with subsequent login attempts to identify potential account takeover patterns

How to Mitigate CVE-2026-2895

Immediate Actions Required

• Audit all FunAdmin installations to identify systems running vulnerable versions (up to 7.1.0-rc4)
• Implement network-level access controls to restrict access to the password recovery functionality if possible
• Enable additional logging and monitoring for the affected endpoints
• Consider temporarily disabling the password recovery feature if it's not business-critical until a patch is available

Patch Information

At the time of publication, the vendor (FunAdmin) has not responded to disclosure attempts and no official patch has been released. Organizations should monitor the FunAdmin project for updates and security advisories. Given the vendor's lack of response, consider evaluating alternative solutions or implementing compensating controls.

Workarounds

• Implement additional verification steps such as email confirmation with time-limited tokens before allowing password changes
• Add IP-based rate limiting on the password reset endpoint to slow down potential attacks
• Consider implementing CAPTCHA or similar bot prevention mechanisms on the password recovery form
• Deploy a web application firewall with custom rules to validate the format and entropy of forget_code and vercode parameters
• Restrict access to the FunAdmin admin interface to trusted IP addresses where feasible

# Example: Rate limiting configuration for nginx
# Add to server or location block for the password reset endpoint
limit_req_zone $binary_remote_addr zone=password_reset:10m rate=5r/m;

location ~ /Member/repass {
    limit_req zone=password_reset burst=2 nodelay;
    # Additional security headers
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-Frame-Options "DENY" always;
}