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. 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.
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.
Sources
Enriched from CVE.org, FIRST EPSS, CISA KEV, GitHub Security Advisories, public proof-of-concept repositories. Last verified by Threadlinqs on .