# CVE-2026-54420 — LiteSpeed Technologies cPanel Plugin **CISA KEV** > As of 2026-06-16, CVE-2026-54420 is a HIGH-severity vulnerability in LiteSpeed Technologies cPanel Plugin, CVSS v3.1 8.5, EPSS 0.8% (55.5th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-06-15), with a US federal remediation deadline of 2026-06-18. Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-54420, most recently “CVE-2026-54420 — LiteSpeed cPanel Plugin Symlink-Following (CWE-61) Privilege Escalation to Root on CloudLinux/CageFS Shared Hosting; Added to CISA KEV After In-the-Wild Exploitation”. **Last updated:** 2026-06-16 ## What is CVE-2026-54420? 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. The record classifies CVE-2026-54420 under weakness class [CWE-61](https://cwe.mitre.org/data/definitions/61.html). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 136 days ago. ## Severity and exploitation probability - **CVSS v3.1 base score:** 8.5 — HIGH (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H`) - **EPSS (FIRST):** 0.8% probability of exploitation in the next 30 days, higher than 55.5% of all scored CVEs - **CISA KEV:** Listed since 2026-06-15, federal remediation deadline 2026-06-18 - **Threadlinqs priority:** 9/10 — CISA KEV-listed, which Threadlinqs floors at 9 - **Published:** 2026-06-14, last modified 2026-06-16 ## Is CVE-2026-54420 being exploited? CISA added CVE-2026-54420 to the Known Exploited Vulnerabilities catalog on 2026-06-15, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2026-06-18 under BOD 22-01. Weaponised exploit code for CVE-2026-54420 is publicly available. 4 public proof-of-concept repositories are tracked for this identifier. It currently carries a trending score of 37 in the Threadlinqs vulnerability feed. - [mahfuzreham/litespeed-cpanel-cve-2026-54420-fix](https://github.com/mahfuzreham/litespeed-cpanel-cve-2026-54420-fix) (github) - [HORKimhab/CVE-2026-54420](https://github.com/HORKimhab/CVE-2026-54420) (github) - [Resellnom/litespeed-cpanel-cve-2026-54420-fix](https://github.com/Resellnom/litespeed-cpanel-cve-2026-54420-fix) (github) - [fevar54/CVE-2026-54420-LiteSpeed-Symlink-Exploit](https://github.com/fevar54/CVE-2026-54420-LiteSpeed-Symlink-Exploit) (github) ## Affected products and versions - **LiteSpeed Technologies**: cPanel Plugin ## How to fix CVE-2026-54420 Because CVE-2026-54420 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2026-06-18. No vendor patch reference has been recorded for CVE-2026-54420 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise. ## Threat activity tracking CVE-2026-54420 1 tracked threat in the Threadlinqs corpus references CVE-2026-54420, either in the campaign’s CVE list or as an indicator on the campaign record. - [CVE-2026-54420 — LiteSpeed cPanel Plugin Symlink-Following (CWE-61) Privilege Escalation to Root on CloudLinux/CageFS Shared Hosting; Added to CISA KEV After In-the-Wild Exploitation](https://intel.threadlinqs.com/threat/TL-2026-0872) — HIGH · 2026-06-19 ## Sources Enriched from CVE.org, FIRST EPSS, CISA KEV, GitHub Security Advisories, public proof-of-concept repositories. Last verified by Threadlinqs on 2026-10-10. **Other references** - [litespeedtech.com](https://www.litespeedtech.com/products/litespeed-web-server/control-panel-support/cpanel) - [blog.litespeedtech.com](https://blog.litespeedtech.com/2026/06/01/security-update-for-litespeed-cpanel-plugin-2/) Canonical: https://intel.threadlinqs.com/cve/CVE-2026-54420 Full detection coverage and IOCs for threats exploiting CVE-2026-54420 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp