XSS in Wpforms Pro
CVE-2026-18409
The WPForms Pro plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Single Line Text and Paragraph Text Field Values in all versions up to, and including, 2.0.0.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The exploit relies on the plugin's own wp_kses_allowed_html filter widening the 'post' allowlist to permit iframe elements with a data-src attribute, which is not on WordPress's URI-attribute sanitization list, allowing a javascript: URI stored in data-src to survive kses processing and subsequently be promoted to a live src attribute by the bundled admin script view-entry.min.js.
Vulnerability class: XSS (Cross-Site Scripting)
CVSS v3 metric
CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N.
Affected products
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-18409?
- CVE-2026-18409 is a high-severity vulnerability in Wpforms Pro, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-08-21.
- How severe is CVE-2026-18409?
- High severity. CVSS v3 base score is 7.2 out of 10.