CVE-2025-13731

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

6.4 Medium

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: Low
Integrity: Low
Availability: None

Exploit likelihood

0.25%Up 0.2 points since Dec 3, 2025

What each source reports

CVE List Score used 6.4

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

Record: CVE-2025-13731
CVSS 3.1: 6.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

EUVDEUVD-2025-200241 6.4

Record: EUVD-2025-200241
CVSS 3.1: 6.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-vjv3-j4fq-22rw 6.4

The Nexter Extension – Site Enhancements Toolkit plugin for WordPress is vulnerable to Stored...

Record: GHSA-vjv3-j4fq-22rw
CVSS 3.1: 6.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

NVD 6.4

Record: CVE-2025-13731
CVSS 3.1: 6.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

Affected products

posimyththemes nexter extension – security, performance, code snippets & site toolkit

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2025-13731 is a medium vulnerability (CVSS 6.4) in Posimyththemes Nexter Extension – Security, Performance, Code Snippets & Site Toolkit, published December 2, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.25%, the 15th percentile. No source names a fixed version.