CVE-2026-54420: LiteSpeed cPanel Plugin UNIX Symbolic Link (Symlink) Following Vulnerability

What it is

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.

Exploitation evidence

First exploit evidence seen: 2026-06-15 (earliest date across the sources below).

Exploited in the wild

• CISA KEV: listed since 2026-06-15. Source

Public exploit code

GitHub proof-of-concept repositories

4 public repositories from 4 accounts, first seen 2026-06-16. Most starred: mahfuzreham/litespeed-cpanel-cve-2026-54420-fix (3 stars), view repository.

Verify before running: public PoCs can be malicious. Read the code and only run it in an isolated lab. A PoC means exploit code is public, not that this CVE is exploited in the wild.

Sources: CISA KEV · nomi-sec/PoC-in-GitHub.

How to fix it

CISA required action

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines. (source: CISA KEV)

Fixed versions

• litespeedtech litespeed cpanel plugin: upgrade to 2.4.8 or later
• litespeedtech litespeed whm plugin: upgrade to 5.3.2.0 or later

Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.

Vendor advisories and patches

• https://blog.litespeedtech.com/2026/06/01/security-update-for-litespeed-cpanel-plugin-2/ (CISA KEV notes)

MITRE ATT&CK mitigations for this chain

• M1042 Disable or Remove Feature or Program (for T1505.003) : Consider disabling functions from web technologies such as PHP’s `evaI()` that may be abused for web shells.
• M1018 User Account Management (for T1505.003) : Enforce the principle of least privilege by limiting privileges of user accounts so only authorized accounts can modify the web directory.

Detection Generic guidance

• Persistence: Look for new files in web roots, new scheduled tasks/services, and new accounts created after the exposure window.

Response checklist Generic guidance

1. Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
2. Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
3. Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
4. Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.