PT-2026-34288 · Ksolves · Captcha

Muhammad Afnaan · Published 2026-04-22 · Updated 2026-04-22 · CVE-2026-4121

Mitre

CVSS v3.1

4.3

Medium

AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

The Kcaptcha plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to and including 1.0.1. This is due to missing nonce validation in the plugin's settings page handler (admin/setting.php). The settings form does not include a wp nonce field() and the form processing code does not call wp verify nonce() or check admin referer() before saving settings to the database via $wpdb->update(). This makes it possible for unauthenticated attackers to modify the plugin's CAPTCHA settings (enabling or disabling CAPTCHA on login, registration, lost password, and comment forms) via a forged request, granted they can trick a site administrator into performing an action such as clicking a link.

Fix

CSRF

Weakness Enumeration

CWE-352

Related Identifiers

CVE-2026-4121

Affected Products

Captcha

References · 8

• https://nvd.nist.gov/vuln/detail/CVE-2026-4121 · Security Note
• https://plugins.trac.wordpress.org/browser/kcaptcha/tags/1.0.1/admin/setting.php#L30 · Note
• https://plugins.trac.wordpress.org/browser/kcaptcha/tags/1.0.1/admin/setting.php#L47 · Note
• https://plugins.trac.wordpress.org/browser/kcaptcha/trunk/admin/setting.php#L47 · Note
• https://wordfence.com/threat-intel/vulnerabilities/id/a6c1c73b-76e3-4cb9-ad53-9d5d4e7519c9?source=cve · Note
• https://plugins.trac.wordpress.org/browser/kcaptcha/trunk/admin/setting.php#L12 · Note
• https://plugins.trac.wordpress.org/browser/kcaptcha/tags/1.0.1/admin/setting.php#L12 · Note
• https://plugins.trac.wordpress.org/browser/kcaptcha/trunk/admin/setting.php#L30 · Note