Improper access control in LiteSpeed User-End cPanel Plugin and LiteSpeed WHM Plugin - CVE-2026-54420
Published: June 16, 2026
Vulnerability identifier: #VU134649
CSH Severity: Critical
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:A/U:Red
CVE-ID: CVE-2026-54420
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
The vulnerability is being exploited in the wild
Vendor: LiteSpeed Technologies
Affected software:
LiteSpeed User-End cPanel Plugin
LiteSpeed WHM Plugin
LiteSpeed User-End cPanel Plugin
LiteSpeed WHM Plugin
Detailed vulnerability description
The vulnerability allows a remote user to escalate privileges to root.
The vulnerability exists due to improper access control in the LiteSpeed cPanel user-end plugin when handling cPanel JSON API requests. A remote user can invoke crafted requests to vulnerable plugin functionality to escalate privileges to root.
Exploitation requires FTP access or web shell access on shared hosting servers running CloudLinux/CageFS.
Note, the vulnerability is being actively exploited in the wild.
How to mitigate CVE-2026-54420
Install security update from vendor's website.