CVE-2025-12813: Strix-BUBOL5 Holiday Class Post Calendar

Critical severity, CVSS 9.8. EPSS: 0.9% chance of exploitation in the next 30 days.

The Holiday class post calendar plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 7.1 via the 'contents' parameter. This is due to a lack of sanitization of user-supplied data when creating a cache file. This makes it possible for unauthenticated attackers to execute code on the server.

Affected products

• Strix-BUBOL5 Holiday Class Post Calendar: up to and including 7.1

Published 2025-11-11. Last modified 2026-06-17.