CVE-2026-7493 Denial of service in Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin

Medium 5.3 Published Updated

Unauthenticated attackers can exhaust PHP worker processes via a REST API endpoint, causing denial of service for legitimate users.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
None listed

What is CVE-2026-7493?

CVE-2026-7493 is a medium-severity denial of service vulnerability in croixhaug Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin, published on 27 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to denial of service in all versions up to, and including, 1.6.11.5. This is due to a publicly accessible REST API endpoint (/wp-json/ssa/v1/async) that calls PHP's sleep() function on a user-supplied delay parameter without any rate limiting. This makes it possible for unauthenticated attackers to exhaust PHP worker processes, denying access to the site to legitimate users.

Weakness: CWE-400

Which versions are affected by CVE-2026-7493?

How do I fix CVE-2026-7493?

No fix has been published for CVE-2026-7493 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-7493 being exploited?

There is no known exploitation of CVE-2026-7493 in the wild and no public exploit code.

Sources

Also known as GHSA-599f-5f93-g6j8.

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