CVE-2026-3367

The Lockme OAuth2 calendars integration plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'App ID' setting in all versions up to, and including, 2.11.0. This is due to insufficient input sanitization and output escaping. The register_setting() call on line 197 lacks a sanitize callback, allowing unsanitized data to be stored via update_option(). When the settings page is rendered, the stored value is echoed directly into an HTML input's value attribute without esc_attr() on line 212. This makes it possible for authenticated attackers, with administrator-level access and above, to inject arbitrary web scripts in the settings page that will execute whenever a user accesses the plugin settings page. Multiple fields are affected: App ID (client_id), App Secret (client_secret), Bookings ID prefix (id_prefix), and API domain (api_domain). This vulnerability is particularly impactful in WordPress multisite installations where administrators of individual sites should not be able to execute JavaScript affecting other users.

• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/lockme-calendars-integration/tags/2.9.3/src/Plugin.php#L197
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/lockme-calendars-integration/tags/2.9.3/src/Plugin.php#L212
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/lockme-calendars-integration/tags/2.9.3/src/Plugin.php#L223
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/lockme-calendars-integration/tags/2.9.3/src/Plugin.php#L245
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/lockme-calendars-integration/tags/2.9.3/src/Plugin.php#L256
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/lockme-calendars-integration/tags/2.9.3/src/Plugin.php#L54
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/lockme-calendars-integration/trunk/src/Plugin.php#L197
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/lockme-calendars-integration/trunk/src/Plugin.php#L212
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/lockme-calendars-integration/trunk/src/Plugin.php#L223
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/lockme-calendars-integration/trunk/src/Plugin.php#L245
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/lockme-calendars-integration/trunk/src/Plugin.php#L256
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/browser/lockme-calendars-integration/trunk/src/Plugin.php#L54
• plugins.trac.wordpress.orghttps://plugins.trac.wordpress.org/changeset?reponame=&old=3495564%40lockme-calendars-integration&new=3495564%40lockme-calendars-integration
• www.wordfence.comhttps://www.wordfence.com/threat-intel/vulnerabilities/id/800b1a44-4173-4b8e-bc69-9a64218e64d6?source=cve