CVE-2026-100151: medium-severity vulnerability in kstover Ninja Forms – Contact Form Builder…
Ninja Forms <= 3.15.5 - Reflected DOM-Based Cross-Site Scripting via 'querystring:<key>' URL Parameter
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.1epss 0.2%
The Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder plugin for WordPress is vulnerable to Reflected DOM-Based Cross-Site Scripting via 'querystring:<key>' URL Parameter in all versions up to, and including, 3.15.5 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link. This bypass is triggered when an attacker supplies a matching field:<key> URL parameter that causes the server to fully resolve the {field:*} placeholder, forcing the client-side else-branch to abandon the server-sanitized value and reconstruct field content from the raw query string.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Affected products
kstover · Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form BuilderRelated CVEs — kstover Ninja Forms – Contact Form Builder…
In the same product, most dangerous first.
CVE-2026-94504HIGHNinja Forms – The Contact Form Builder That Grows With You <= 3.15.3 - Stored Cross-Site ScriptingEPSS 0.6%CVE-2026-100155MEDIUMNinja Forms <= 3.15.5 - Unauthenticated Arbitrary Shortcode Execution via 'formData' Field Value via Success Message Merge TagEPSS 0.5%CVE-2026-109997HIGHNinja Forms <= 3.15.5 - Unauthenticated Stored Cross-Site Scripting via 'extra' Parameter via Metadata Key NormalizationEPSS 0.4%CVE-2026-101326MEDIUMNinja Forms <= 3.15.5 - Authenticated (Subscriber+) Arbitrary Shortcode Execution via '{wp:user_display_name}' Merge Tag via display_nameEPSS 0.4%CVE-2026-90438HIGHNinja Forms <= 3.15.4 - Unauthenticated Stored Cross-Site Scripting via Paragraph Text (RTE) Field SubmissionEPSS 0.3%
References
https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.4/assets/js/min/front-end.jshttps://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.4/includes/MergeTags/Other.php#L41https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.4/includes/Templates/fields-html.html#L2https://plugins.trac.wordpress.org/changeset/3749135/ninja-forms/trunk/assets/js/min/front-end.jshttps://wordpress.org/plugins/ninja-forms/https://www.wordfence.com/threat-intel/vulnerabilities/id/82ace2e3-1120-4be9-a7c6-b64590c8a35f?source=cve