HIGH · CVSS 8.5 CISA Known Exploited Vulnerability

CVE-2026-54420

LiteSpeed cPanel Plugin UNIX Symbolic Link (Symlink) Following Vulnerability

LiteSpeed cPanel Plugin

LiteSpeed cPanel plugin before 2.4.8 (as distributed in LiteSpeed WHM PlugIn before 5.3.2.0) mishandles symlinks provided by a user with FTP or web shell access on a shared hosting server running CloudLinux/CageFS, as exploited in the wild in May 2026.

CVSS

8.5

HIGH

EPSS

1.4%

30-day exploitation

Ransomware groups

recorded exploiting

Published

14 Jun 2026

CWE-61

Exploitation status

CISA Known Exploited Vulnerabilities

Listed by CISA on 15 June 2026. US federal agencies were required to remediate it by 18 June 2026.

EPSS — exploitation probability

FIRST puts the probability of exploitation activity in the next 30 days at 1.4%, which is higher than 73.3% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Frequently asked questions

Is CVE-2026-54420 being exploited by ransomware groups?

No ransomware group in this database is currently recorded as exploiting CVE-2026-54420.

What does CVE-2026-54420 affect?

CVE-2026-54420 affects LiteSpeed cPanel Plugin. LiteSpeed cPanel plugin before 2.4.8 (as distributed in LiteSpeed WHM PlugIn before 5.3.2.0) mishandles symlinks provided by a user with FTP or web shell access on a shared hosting server running CloudLinux/CageFS, as exploited in the wild in May 2026.

How severe is CVE-2026-54420?

CVE-2026-54420 is rated HIGH with a CVSS base score of 8.5. EPSS puts the probability of exploitation in the next 30 days at 1.4%, higher than 73.3% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 18 June 2026.

How should organisations respond to CVE-2026-54420?

Apply the vendor patch for LiteSpeed cPanel Plugin as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.