Zero-day vulnerability in cPanel

Improper authentication
CVE-2026-41940

Vulnerability details

Advisory: SB2026043060 - Authentication bypass in cPanel & WHM

Vulnerable component: cPanel

CVE-ID: CVE-2026-41940

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C

CWE-ID: CWE-287 - Improper Authentication

Description:

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to an error in the authentication process. A remote non-authenticated attacker can bypass authentication process and gain unauthorized access to the application.

Successful exploitation of the vulnerability may result in full system compromise. 

Note, the vulnerability is being actively exploited in the wild. 

External links:

https://support.cpanel.net/hc/en-us/articles/40073787579671-Security-CVE-2026-41940-cPanel-WHM-WP2-Security-Update-04-28-2026
https://success.trendmicro.com/en-US/solution/KA-0023294

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.