XSS in Posimyththemes Nexter Extension – Security, Performance, Code Snippets & Site Toolkit

CVE-2025-13731

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (12.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 12.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-13731: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-13731?
CVE-2025-13731 is a medium-severity vulnerability in Posimyththemes Nexter Extension – Security, Performance, Code Snippets & Site Toolkit, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2025-12-02.
How severe is CVE-2025-13731?
Medium severity. CVSS v3 base score is 6.4 out of 10.