CVE-2026-7493

Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin <= 1.6.11.5 - Unauthenticated Denial of Service

2026-05-26 13:07
lucky_buddy

Strategic Overview

Status
Patched in 1.6.11.7
Affected Plugin
Simply Schedule Appointments
Affected Version
<= 1.6.11.5
CVSS
5.3Medium
Weakness type
CWE-400 · Uncontrolled Resource Consumption
CVE
CVE-2026-7493
View all Simply Schedule Appointments vulnerabilities

At a glance

CVE-2026-7493 is a medium-severity Uncontrolled Resource Consumption vulnerability in the Simply Schedule Appointments WordPress plugin, affecting versions <= 1.6.11.5. It carries a CVSS score of 5.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 1.6.11.7; sites on affected versions should update now. Disclosed May 2026, reported by lucky_buddy.

Vulnerability Overview

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.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user.

CWE-400: Uncontrolled Resource Consumption

Simply Schedule Appointments <= 1.6.11.5 carries this weakness at sleep(), and reaching it takes no account at all. Uncontrolled resource consumption means a request can make the server do an amount of work it never bounds, because the size or repetition of the job is taken from the request rather than capped by the code.

A single caller can hold PHP workers, database connections or disk open long enough to slow the site for everyone, without needing any account or any other flaw. For Simply Schedule Appointments the fix is 1.6.11.7: builds <= 1.6.11.5 are affected, anything from 1.6.11.7 onward is not.

Remediation

Update to version 1.6.11.7, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Simply Schedule Appointments 1.6.11.7 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-7493https://www.wordfence.com/threat-intel/vulnerabilities/id/ae66228e-d086-44fd-8acb-5a99482cedfbhttps://nvd.nist.gov/vuln/detail/CVE-2026-7493

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C