CVE-2026-3264: Free-CRM RCE Vulnerability

CVE-2026-3264 Overview

A vulnerability has been identified in go2ismail Free-CRM affecting versions up to commit b83c40a90726d5e58f0cc680ffdcaa28a03fb5d1. This Execution After Redirect (EAR) vulnerability exists within the Administrative Interface component, allowing attackers to bypass authorization controls through client-side redirect manipulation. The vulnerability can be exploited remotely and has been publicly disclosed.

Critical Impact

Attackers can bypass authorization controls in the Administrative Interface, potentially gaining unauthorized access to administrative functions and escalating privileges within the CRM system.

Affected Products

• go2ismail Free-CRM (up to commit b83c40a90726d5e58f0cc680ffdcaa28a03fb5d1)
• Free-CRM Administrative Interface component
• All rolling release versions prior to the fix

Discovery Timeline

• 2026-02-26 - CVE-2026-3264 published to NVD
• 2026-02-26 - Last updated in NVD database

Technical Details for CVE-2026-3264

Vulnerability Analysis

This vulnerability is classified as CWE-698 (Execution After Redirect), a weakness where a web application fails to properly halt execution after issuing a redirect response. In the context of Free-CRM's Administrative Interface, when an unauthorized user attempts to access protected administrative functionality, the application issues a redirect but continues processing the original request. This allows attackers to intercept or ignore the redirect response while the server completes the execution of privileged operations.

The attack can be launched remotely over the network and requires only low-level privileges to execute. The impact includes potential compromise of confidentiality, integrity, and availability at a limited scope, as attackers may access, modify, or disrupt administrative functions that should be restricted.

Root Cause

The root cause lies in improper server-side authorization enforcement within the Administrative Interface. Rather than terminating request processing immediately after determining that a user lacks proper authorization, the application merely issues a client-side redirect response. The server continues executing the requested functionality, assuming the client will obey the redirect instruction. Since the redirect is only enforced client-side, attackers using intercepting proxies or custom HTTP clients can simply ignore the redirect and receive the response from the completed privileged operation.

Attack Vector

The attack is executed remotely over the network. An attacker with basic authentication to the Free-CRM system can:

1. Intercept HTTP responses from the Administrative Interface using a proxy tool
2. Identify redirect responses (HTTP 302/303) that attempt to deny access to administrative functions
3. Ignore or suppress the redirect while capturing the full server response
4. Access administrative functionality or data that should have been protected

The vulnerability enables a privilege escalation scenario where a low-privileged user can bypass client-side redirect-based authorization to access administrative capabilities. The exploit has been publicly disclosed, increasing the risk of active exploitation.

For technical details and proof-of-concept information, refer to the GitHub Privilege Escalation Advisory.

Detection Methods for CVE-2026-3264

Indicators of Compromise

• HTTP responses containing both redirect headers (Location) and administrative content in the response body
• Multiple rapid requests to administrative endpoints from non-administrative user sessions
• Evidence of proxy tools intercepting and modifying redirect responses in access logs
• Unusual access patterns where users access administrative functions without corresponding redirect follow-through

Detection Strategies

• Monitor web application logs for requests to administrative endpoints that return redirect responses but contain unexpected response body content
• Implement server-side logging that correlates user privilege levels with accessed endpoints to identify authorization bypass attempts
• Deploy Web Application Firewall (WAF) rules to detect and alert on potential EAR exploitation patterns
• Audit authentication and session management logs for privilege escalation indicators

Monitoring Recommendations

• Enable verbose logging on the Administrative Interface component to capture full request/response cycles
• Configure alerting for administrative endpoint access by non-administrative accounts
• Review access logs regularly for patterns consistent with redirect bypass attempts
• Monitor for increased traffic to administrative endpoints from previously inactive or low-privilege user accounts

How to Mitigate CVE-2026-3264

Immediate Actions Required

• Restrict access to the Administrative Interface to trusted networks or IP ranges until a patch is available
• Implement additional server-side authorization checks that terminate request processing immediately upon failed authorization
• Review user accounts and remove unnecessary administrative privileges
• Monitor for signs of exploitation using the detection methods outlined above

Patch Information

The vendor (go2ismail) was contacted regarding this disclosure but did not respond. Free-CRM implements a rolling release model, meaning specific version numbers for affected or patched releases are unavailable. Organizations should monitor the Free-CRM GitHub repository and VulDB entry for updates regarding fixes.

Workarounds

• Implement server-side middleware that ensures request processing terminates immediately after issuing redirect responses
• Add explicit exit() or return statements after all redirect calls in the Administrative Interface code
• Deploy a reverse proxy or WAF rule that strips response bodies from redirect responses to prevent information leakage
• Limit Administrative Interface access to VPN-only or internal network connections until the vulnerability is addressed

# Example nginx configuration to restrict administrative interface access
location /admin {
    # Restrict to internal network only
    allow 10.0.0.0/8;
    allow 192.168.0.0/16;
    deny all;
    
    # Additional logging for security monitoring
    access_log /var/log/nginx/admin_access.log combined;
    error_log /var/log/nginx/admin_error.log warn;
}