CVE-2026-12111: Appointment Booking Calendar: Sensitive Information Exposure

Appointment Booking Calendar: Sensitive Information Exposure

The Appointment Booking Calendar plugin for WordPress is vulnerable to Sensitive Information Exposure in versions up to, and including, 1.4.01. This is due to insufficient authorization and missing per-calendar ownership checks in the cpabc_appointments_calendar_load2() function, which is reachable via the cpabc_calendar_load2=1 query parameter in wp-admin and only checks is_admin() && current_user_can('edit_posts'), a capability available to Contributor-level users and above. This makes it possible for authenticated attackers with Contributor-level access and above to supply an arbitrary calendar ID via the id parameter and extract customer booking information, including email addresses, names, phone numbers, booking times, and comments, from any calendar managed by the plugin.

Description from the National Vulnerability Database, published by Wordfence

What it means for a small business

Appointment Booking Calendar is a WordPress plugin. If your website uses it, the flaw is on your site whether or not anyone has noticed yet: attackers scan the whole internet for the plugins with published flaws, usually within days of a record like this one going public.

Most small-business sites run 15 to 40 plugins, and few owners know the list. You can check from WordPress itself (Plugins, then Installed Plugins), or let our free plugin check look it up by name.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.28%, higher than 20% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 28, 2026, updated daily.

Check your own setup

Is Appointment Booking Calendar safe? Every recorded flaw in it, the version that fixes each, and whether it’s still maintained.
Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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