CVE-2025-54001

CRITICAL 9.8

WordPress Classter theme <= 2.5 - PHP Object Injection vulnerability

CVSS Score

9.8

EPSS Score

0.0%

EPSS Percentile

0th

Deserialization of Untrusted Data vulnerability in ThemeREX Classter classter allows Object Injection.This issue affects Classter: from n/a through <= 2.5.

CWE	CWE-502
Vendor	themerex
Product	classter
Published	Mar 5, 2026
Last Updated	Apr 28, 2026

Stay Ahead of the Next One

Get instant alerts for themerex classter

Be the first to know when new critical vulnerabilities affecting themerex classter are published — delivered to Slack, Telegram or Discord.

Get Free Alerts → Free · No credit card · 60 sec setup

CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

ThemeREX / Classter

0 ≤ 2.5

References

NVD ↗ CVE.org ↗ EPSS Data ↗

patchstack.com: https://patchstack.com/database/Wordpress/Theme/classter/vulnerability/wordpress-classter-theme-2-5-php-object-injection-vulnerability?_s_id=cve

Credits

Tran Nguyen Bao Khanh (VCI - VNPT Cyber Immunity) | Patchstack Bug Bounty Program