Security Advisory 2026-02-27

Unauthenticated account creation vulnerability in phpMyFAQ

Issued on:
2026-02-27
Software:
phpMyFAQ <= 4.0.17
Risk:
High
Platforms:
all

The phpMyFAQ Team has learned of security issues that'd been discovered in phpMyFAQ 4.1.0-RC.6, and earlier.

Description

The WebAuthn prepare endpoint (/api/webauthn/prepare) creates new active user accounts without any authentication,

CSRF protection, or configuration checks. This allows unauthenticated attackers to create unlimited user accounts even

when registration is disabled.

Solution

The phpMyFAQ Team has released the new phpMyFAQ versions 4.0.18 and 4.1.0-RC.7, which fix the vulnerability. All

users of affected phpMyFAQ versions are encouraged to upgrade as soon as possible to this latest version.

Workaround

There's no workaround except installing phpMyFAQ 4.0.18 or 4.1.0-RC.7.

Thanks

The phpMyFAQ team would like to thank **Offensive-AI** for the responsible disclosures of this vulnerability.