CVE-2026-18315 (CVSS 9.8)

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.

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CVSS v3.1 Score

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0060

Probability of exploitation

0.47%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-639 CWE-639

References

Other References

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/main/function_ajax.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://www.wordfence.com/threat-intel/vulnerabilities/id/73251a74-5be3-446b-8e0a-ff2d1484c467?source=cve

Frequently Asked Questions

What is CVE-2026-18315? +

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. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2026-18315? +

CVE-2026-18315 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0060, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-18315? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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