CVE-2026-4118: WordPress Call To Action Plugin CSRF Flaw

CVE-2026-4118 Overview

CVE-2026-4118 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the Call To Action Plugin for WordPress in all versions up to and including 3.1.3. The flaw resides in the cbox_options_page() function, which manages saving, creating, and deleting plugin settings without performing nonce validation. Unauthenticated attackers can modify call-to-action box titles, content, link URLs, image URLs, colors, and other configuration parameters by tricking an authenticated administrator into clicking a crafted link. The vulnerability is tracked under [CWE-352] (Cross-Site Request Forgery).

Critical Impact

Attackers can manipulate call-to-action content displayed to site visitors, including injecting malicious link URLs that redirect users to phishing or malware distribution pages.

Affected Products

• Call To Action Plugin for WordPress, versions through 3.1.3
• All site installations exposing the plugin settings page to administrator sessions
• WordPress sites where administrators can be targeted via social engineering

Discovery Timeline

• 2026-04-22 - CVE CVE-2026-4118 published to NVD
• 2026-04-22 - Last updated in NVD database

Technical Details for CVE-2026-4118

Vulnerability Analysis

The Call To Action Plugin renders its settings form through the cbox_options_page() function but omits the standard WordPress wp_nonce_field() call when generating the form HTML. When the form is submitted, the corresponding save handler processes the request directly via $wpdb->update() without invoking wp_verify_nonce() or check_admin_referer(). This absence of request origin verification allows any HTTP POST request reaching the settings endpoint to be processed as legitimate, provided a logged-in administrator's browser delivers it.

An attacker can host a page containing an auto-submitting form or image tag targeting the plugin settings URL. When an authenticated administrator visits the attacker-controlled page, the browser submits the request using the administrator's active session cookies, and the plugin commits the attacker-supplied values to the database.

Root Cause

The root cause is missing CSRF token validation in administrative state-changing operations. WordPress provides built-in primitives — wp_nonce_field() for emission and check_admin_referer() or wp_verify_nonce() for verification — that the plugin author did not implement around the settings save, create, and delete paths.

Attack Vector

Exploitation requires user interaction from a site administrator, such as clicking a malicious link or visiting an attacker-controlled web page while authenticated to the WordPress admin panel. No credentials are required from the attacker. Successful exploitation results in unauthorized modification of plugin configuration. Refer to the Wordfence Vulnerability Report and the WordPress Plugin Source Code for the affected handler locations at lines 41, 55, 69, and 76 of call-to-action-plugin.php.

Detection Methods for CVE-2026-4118

Indicators of Compromise

• Unexpected changes to call-to-action box title, content, link URL, or image URL fields without corresponding admin-initiated activity in WordPress audit logs.
• HTTP POST requests to the plugin settings page originating with a Referer header pointing to an external domain.
• Outbound clicks from site visitors leading to unfamiliar URLs configured in the call-to-action link target.

Detection Strategies

• Compare database values for plugin configuration rows against a known-good baseline on a recurring schedule.
• Inspect web server access logs for POST requests to wp-admin pages where the Referer header is missing or cross-origin.
• Monitor WordPress activity logs for settings updates that lack a matching administrator session in authentication logs.

Monitoring Recommendations

• Forward WordPress access logs and audit trails into a centralized log analytics platform for cross-referencing with admin login events.
• Alert on modifications to plugin option rows in wp_options or plugin-specific tables outside of approved change windows.
• Track outbound link destinations rendered by the plugin and alert on changes to domains not on an approved list.

How to Mitigate CVE-2026-4118

Immediate Actions Required

• Restrict administrator browsing habits and require admins to use a dedicated browser profile or session that is not used for general web browsing.
• Audit current plugin settings and revert any unauthorized changes to title, content, link URL, image URL, and color fields.
• Deploy a web application firewall rule that requires a valid same-origin Referer header on POST requests to the plugin settings endpoint.

Patch Information

No vendor-released fixed version is referenced in the NVD entry at the time of publication. Review the Wordfence Vulnerability Report for any subsequent patch availability and the upstream WordPress Plugin Source Code repository for code updates.

Workarounds

• Deactivate the Call To Action Plugin until a patched release becomes available.
• Restrict access to /wp-admin/ to known administrator IP addresses via web server or firewall rules.
• Enforce administrator use of browser isolation or a session-bound browser profile to reduce CSRF risk during active admin sessions.
• Add a reverse-proxy rule rejecting POST requests to the plugin settings URL when the Referer header is absent or external.

# Example nginx rule to reject cross-origin POSTs to wp-admin
location ~ ^/wp-admin/ {
    if ($request_method = POST) {
        if ($http_referer !~* "^https?://your-site\.example/") {
            return 403;
        }
    }
}