CVE-2026-4121 Details
Description
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.
A Cross-Site Request Forgery (CSRF) vulnerability has been identified in the Kcaptcha plugin for WordPress, affecting all versions up to and including 1.0.1. The vulnerability arises from a lack of nonce validation in the plugin's settings page handler. Specifically, the settings form fails to include a nonce field, and the form processing code does not verify the nonce or check the admin referer before saving settings to the database. This oversight allows unauthenticated attackers to manipulate the plugin's CAPTCHA settings by sending a forged request, provided they can deceive a site administrator into clicking a link.
No known patch is available for this vulnerability. It is recommended to review the vulnerability details and consider uninstalling the affected plugin.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Apr 22, 2026CISA-ADP
Assessed Apr 23, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-352 | Cross-Site Request Forgery (CSRF) | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Kcaptcha | All versions |
CPE
Remediation
| |
Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Apr 22, 2026 | New CVE Received | [email protected] |