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

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Yes, if you run LiteSpeed cPanel Plugin. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-06-15, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-06-18; treat that as the outer limit, not the target.
• EPSS 0.8%, percentile 56: FIRST’s model estimates a 0.8% chance of exploitation activity in the next 30 days, higher than 56% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Needs an account (low (any account)). Exposure depends on who can log in.

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.

CISA’s summary

LiteSpeed cPanel plugin contains a UNIX symbolic link (Symlink) following vulnerability that could allow a user with FTP or web shell access on a shared hosting server running CloudLinux/CageFS.

Weakness type: CWE-61.

Product: LiteSpeed cPanel Plugin · Assigned by: mitre · Published: 2026-06-14

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: high (needs special conditions)
• Privileges required: low (any account)
• User interaction: none
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: added 2026-06-15; federal due date 2026-06-18. Known ransomware use: Unknown.
• 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.
• CISA SSVC assessment: exploitation active, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.81% probability of exploitation activity in the next 30 days; percentile 56.

Timeline

• 2026-06-14 — CVE record published by mitre
• 2026-06-15 — Added to CISA’s Known Exploited Vulnerabilities catalog
• 2026-06-16 — CVE record last updated
• 2026-06-18 — CISA remediation deadline for US federal agencies

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. Listed in CISA KEV notes (blog.litespeedtech.com) blog.litespeedtech.com

Vulnerability records

1. CVE.org record CVE-2026-54420 cve.org
2. NVD entry CVE-2026-54420 nvd.nist.gov

Government

1. CISA Known Exploited Vulnerabilities catalog entry cisa.gov
2. Listed in CISA KEV notes (cisa.gov) cisa.gov
3. Listed in CISA KEV notes (cisa.gov) cisa.gov

Other references from the CVE record and advisory

1. litespeedtech.com litespeedtech.com

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