itsismarcos/cve-2026-41940Automated exploit for CVE-2026-41940, an authentication bypass in cPanel/WHM, allowing unauthorized administrative access to vulnerable servers.
The recent CVE-2026-41940 vulnerability has raised great concern among server administrators using cPanel/WHM. It is a critical flaw that can allow authentication bypass, enabling unauthorized access to the administrative panel without valid credentials.
Considering that WHM is the main control point for servers hosting multiple services, this vulnerability represents a direct risk of total environment compromise.
What is CVE-2026-41940? CVE-2026-41940 is a security flaw that affects certain versions of cPanel/WHM and allows an attacker to bypass the authentication mechanism. In practice, this means that, depending on the installed version, an attacker can gain administrative access to the server.
This type of vulnerability is classified as critical, as it does not necessarily depend on compromised credentials or complex attacks.
This vulnerability is being actively exploited!
Who is at risk? Servers using cPanel versions below the official fixes are potentially vulnerable. Among the most critical scenarios are:
Environments without IP access restrictions Infrastructures without automatic updates enabled How to check if your server is vulnerable The first step is to check the installed cPanel version:
/usr/local/cpanel/cpanel -V Compare it with the fixed versions released by the vendor. If you are using a lower version within the same branch, an immediate update is highly recommended.
Additionally, simple tests can indicate improper exposure, such as requests to internal endpoints returning data without proper authentication.
How to fix the vulnerability The most effective way to fix it is to update cPanel to the latest version:
/scripts/upcp --force After the update, it is recommended to restart the services:
/scripts/restartsrv_cpsrvd --hard Immediate mitigation measures If updating is not possible immediately, some actions can reduce the risk:
Restrict access to ports 2083 and 2087 by IP Warning: If your server is accessed by clients (for example, hosting reselling), restricting the ports will mean your clients WILL NOT BE ABLE to access WHM/cPanel Use VPN for administrative access Implement firewall rules (iptables or security groups) Use a WAF (such as Cloudflare) for additional protection Security best practices In addition to fixing the vulnerability, it is important to maintain a continuous security posture:
Regular system updates Monitoring of WHM access Use of multi-factor authentication (2FA) Periodic log auditing Conclusion CVE-2026-41940 highlights the importance of keeping systems always updated and protected. Critical vulnerabilities like this can be exploited quickly after disclosure, making immediate action essential.
How to use it in your terminal:
To attack WHM (port 2087): python3 CVE-2026-41940.py exemplo.com To attack the user panel (port 2083): python3 CVE-2026-41940.py exemplo.com -p 2083
