CVE-2026-11866
The Appointment Booking Plugin WordPress plugin before 5.6.3 does not validate a CSRF nonce on several state-changing actions handled by its central request dispatcher, allowing attackers to perform privileged actions, such as overwriting the booking-form configuration or disconnecting the connected payment gateway, via Cross-Site Request Forgery against a logged-in administrator.
No public exploitation has been reported so far. No distribution fix is listed yet; apply vendor mitigations and monitor.
Recommended action: Track your distribution's security tracker and apply the fix as soon as it ships.
Severity metrics
CVSS 3.1 : 5.4 MEDIUM
Vector: AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L
Affected & fixed versions by distribution
Versions are the native distribution strings (backport-aware): RHEL/Debian/SUSE backport fixes, so compare with the distro version comparator (dpkg / rpm / vercmp), not the upstream version.
No affected package in the tracked watchlist yet (Debian, Ubuntu, Arch, SUSE, Red Hat...). Triage may still be pending.