How severe is CVE-2026-54420?

CVE-2026-54420 has a CVSS score of 8.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-54420?

Affected package information for CVE-2026-54420 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2026-54420?

No fixed version has been published for CVE-2026-54420 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2026-54420 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-54420 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-54420?

CVE-2026-54420 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 26th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-54420?

CVE-2026-54420 is classified as CWE-61 (CWE-61). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2026-54420?

CVE-2026-54420 affects litespeedtech litespeed cpanel plugin; litespeedtech litespeed whm plugin. Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2026-54420 published, and has it been updated?

CVE-2026-54420 was published on June 14, 2026 and was last updated on June 15, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2026-54420: Litespeed Cpanel Plugin CWE-61 (High 8.5)

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk26th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

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.

Affected Products

2 products · 2 configurations

Application

litespeed cpanel pluginlitespeedtech

< 2.4.8

range

Application

litespeed whm pluginlitespeedtech

< 5.3.2.0

range

Frequently Asked Questions

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.

O3 Security · Impact-Aware SCA

Is CVE-2026-54420 in your stack?

O3 detects CVE-2026-54420 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my stack How O3 SCA works