# CVE-2026-16142: Auth bypass in TrueBooker – Appointment Booking and Scheduler System

> Unauthenticated attackers can take over any WordPress account, including administrators, by modifying user email addresses via an insecure AJAX handler.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** GHSA-76x4-wpvp-whc4

## What is CVE-2026-16142?

CVE-2026-16142 is a critical authentication bypass vulnerability in themetechmount TrueBooker – Appointment Booking and Scheduler System, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The TrueBooker plugin for WordPress is vulnerable to Account Takeover in all versions up to, and including, 1.2.6. This is due to the add_front_user_update() AJAX handler being registered for unauthenticated users and accepting an arbitrary truebooker_wp_user_id value, which is passed directly to wp_update_user() without verifying authentication or ownership. This makes it possible for unauthenticated attackers to change any WordPress user account email address, including an administrator, by submitting the target user ID and an attacker-controlled email address. An attacker can then use the native WordPress password reset flow to receive the reset link at the attacker-controlled email address and take over the account.

Weakness: CWE-639 (Authorization Bypass Through User-Controlled Key)

## Which versions are affected by CVE-2026-16142?


## How do I fix CVE-2026-16142?

No fix has been published for CVE-2026-16142 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-16142 being exploited?

There is no known exploitation of CVE-2026-16142 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-16142 and fix it if it is affected.

What it is: CVE-2026-16142 is a critical authentication bypass vulnerability in themetechmount TrueBooker – Appointment Booking and Scheduler System, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-16142 in the wild and no public exploit code.

Affected product: themetechmount TrueBooker – Appointment Booking and Scheduler System. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-16142/ (Markdown: https://insights.sbomify.com/CVE-2026-16142/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-16142
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-16142
- OSV: https://osv.dev/vulnerability/CVE-2026-16142

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-16142/
Summaries are generated and may contain mistakes; the official description above is the record.