Booking Calendar <= 11.8.2 — Authenticated (Editor+) Privilege Escalation to 'data_name' Parameter

Am I affected?

• Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Booking Calendar.
• No admin access? Run a passive check of your site. It reads public files only.

What to do

1. Update to version 11.8.3, or a newer patched version
2. Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
3. Watch Booking Calendar to get an email when the next vulnerability is published.

Advisory

Source description from Wordfence Intelligence, credited to Wordfence PRISM.

The Booking Calendar plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 11.8.2 via the `wpbc_ajax_option_save` AJAX action. The vulnerability exists because the `handle_ajax_save()` function applies per-option safeguards only to names explicitly registered via `register_option_policy()`, causing `get_option_policy()` to return an empty policy — bypassing all can_save, force_mode, and allowed_keys checks — for any unregistered option name, including core WordPress options, while an attacker-controlled `data_name` parameter passes through `sanitize_key()` and is written directly to `update_option()` without restriction. This makes it possible for authenticated attackers with Editor-level access and above to escalate their privileges to Administrator by writing core WordPress options such as `default_role=administrator` and `users_can_register=1`, then self-registering a new Administrator account. The nonce check does not meaningfully restrict this attack, as both the nonce value and nonce action are attacker-supplied POST parameters, and a valid nonce is trivially obtainable via `admin-ajax.php?action=rest-nonce`.

Exploits & references

Proof-of-concept & detection

No public proof-of-concept or detection template is known for this vulnerability.

Advisories & patches

• Advisorywordfence.com

Related CVEs

Timeline

1. Sep 17, 2026

   CVE published

   Severity high, CVSS 7.2

2. Nov 13, 2026

   Record last updated