CVE-2025-13731: Posimyththemes Nexter Extension – Security, Performance, Code Snippets & Site Toolkit

Medium severity, CVSS 6.4. EPSS: 0.2% chance of exploitation in the next 30 days.

The Nexter Extension – Site Enhancements Toolkit plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'nxt-year' shortcode in all versions up to, and including, 4.4.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Affected products

• Posimyththemes Nexter Extension – Security, Performance, Code Snippets & Site Toolkit: up to and including 4.4.1

Published 2025-12-02. Last modified 2026-06-17.