CVE-2025-14160: 
WordPress vulnerability analysis and mitigation

CVE-2025-14160 is a Cross-Site Request Forgery (CSRF) vulnerability in the "Upcoming for Calendly" plugin for WordPress, affecting all versions up to and including 1.2.4. The flaw allows unauthenticated attackers to update the plugin's Calendly API key by tricking a site administrator into clicking a malicious link or visiting a crafted page. It was published on December 12, 2025, with a CVSS v3.1 base score of 4.3 (Medium), assigned by Wordfence (Wordfence, Red Hat CVE).

The vulnerability is classified as CWE-352 (Cross-Site Request Forgery) and stems from missing nonce validation in the plugin's settings update functionality, specifically in includes/settings.php at line 33. Because no CSRF token is verified when processing settings changes, an attacker can craft a forged HTTP request that, when triggered by an authenticated administrator, silently updates the Calendly API key to one controlled by the attacker. Exploitation requires social engineering — the administrator must be tricked into performing an action such as clicking a malicious link while authenticated to the WordPress dashboard (Wordfence, WordPress Trac).

Successful exploitation allows an attacker to replace the site's legitimate Calendly API key with their own, effectively hijacking the integration between the WordPress site and Calendly. This could enable unauthorized access to calendar data, manipulation of scheduling information, and disruption of booking workflows for site visitors. The confidentiality and availability impacts are rated as none, while integrity is rated low — the primary risk is unauthorized modification of plugin configuration rather than full system compromise (Wordfence, Red Hat CVE).

No public proof-of-concept exploit code or in-the-wild exploitation has been reported for CVE-2025-14160. The EPSS score is approximately 0.013% (0.000130), indicating a very low probability of exploitation in the near term. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. Exploitation is constrained by the requirement for administrator interaction, limiting its practical attack surface (Wordfence).

1. Reconnaissance: Identify WordPress sites using the "Upcoming for Calendly" plugin (version ≤ 1.2.4) via public search tools or WordPress plugin enumeration.
2. Craft forged request: Create an HTML page or link containing a hidden form that submits a POST request to the target WordPress site's admin settings endpoint for the plugin, with a malicious Calendly API key as the payload — no CSRF token is required.
3. Social engineering: Deliver the malicious link or page to a site administrator via phishing email, comment, or other channel, enticing them to click while authenticated to the WordPress admin panel.
4. API key replacement: When the administrator loads the attacker-controlled page, the forged request is automatically submitted, updating the plugin's Calendly API key to the attacker's value without any visible indication to the victim.
5. Abuse hijacked integration: Use the substituted API key to access or manipulate the Calendly account data surfaced on the victim's WordPress site (Wordfence, WordPress Trac).

• Logs: WordPress admin action logs showing unexpected changes to the "Upcoming for Calendly" plugin settings, particularly the Calendly API key field, from an administrator account without a corresponding admin session activity.
• File System: Review wp-options database table for unexpected changes to the plugin's API key option value.
• Network: Outbound requests from the WordPress site to Calendly APIs using an unrecognized or attacker-controlled API key.
• Application: Calendly scheduling widgets on the site displaying incorrect or unexpected calendar data not belonging to the site owner.

Update the "Upcoming for Calendly" WordPress plugin to version 1.2.5 or later, which addresses the missing nonce validation in the settings update functionality. The fix was introduced in changeset 3415892 on the WordPress plugin repository. As a temporary workaround, administrators should avoid clicking unsolicited links while logged into the WordPress dashboard and consider disabling the plugin until the update can be applied (WordPress Trac Changeset, WordPress Plugin Page).