What is CVE-2025-5398?

CVE-2025-5398 is a medium-severity vulnerability in Kstover Ninja Forms – The Contact Form Builder That Grows With You, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2025-06-27.

How severe is CVE-2025-5398?

Medium severity. CVSS v3 base score is 6.4 out of 10.

XSS in Kstover Ninja Forms – The Contact Form Builder That Grows With You

CVE-2025-5398

The Ninja Forms – The Contact Form Builder That Grows With You plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the use of a templating engine in all versions up to, and including, 3.10.2.1 due to insufficient output escaping on user data passed through the template. 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 2025-06-27 · last modified 2026-06-17.

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 (14.3th percentile), scored 2026-10-23.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 14.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

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

Affected products

Kstover Ninja Forms – The Contact Form Builder That Grows With You — versions 0
Ninjaforms Ninja Forms

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

www.wordfence.com/threat-intel/vulnerabilities/id/92d106c6-a910-4f41-94d1-59f6b… (Third Party Advisory)
plugins.trac.wordpress.org/browser/ninja-forms/tags/3.10.1/assets/js/min/front-… (Product)
plugins.trac.wordpress.org/changeset (Patch)

Frequently asked questions

What is CVE-2025-5398?: CVE-2025-5398 is a medium-severity vulnerability in Kstover Ninja Forms – The Contact Form Builder That Grows With You, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2025-06-27.
How severe is CVE-2025-5398?: Medium severity. CVSS v3 base score is 6.4 out of 10.