What’s Vulnerable › Vulnerabilities

CVE-2025-13731: Nexter Extension <= 4.4.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode

• Severity: medium (CVSS 6.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-12-02 · updated 2026-10-18
• Weakness: CWE-79

Description

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: through 4.4.1

References

• https://plugins.trac.wordpress.org/browser/nexter-extension/trunk/include/class-nexter-load-ext.php#L136
• https://plugins.trac.wordpress.org/browser/nexter-extension/trunk/include/class-nexter-load-ext.php#L66
• https://plugins.trac.wordpress.org/changeset?old=3402155&old_path=nexter-extension%2Ftags%2F4.4.1%2Finclude%2Fclass-nexter-load-ext.php&new=3403967&new_path=nexter-extension%2Ftags%2F4.4.2%2Finclude%2Fclass-nexter-load-ext.php
• https://www.wordfence.com/threat-intel/vulnerabilities/id/809cd97c-22ea-49e7-be46-688fefe50236?source=cve

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