CVE-2026-27836

phpMyFAQ Allows Unauthenticated Account Creation via WebAuthn Prepare Endpoint

CVSS 7.5 HIGHEPSS 0.4%CWE-862

phpMyFAQ is an open source FAQ web application. Prior to version 4.0.18, the WebAuthn prepare endpoint (`/api/webauthn/prepare`) creates new active user accounts without any authentication, CSRF protection, captcha, or configuration checks. This allows unauthenticated attackers to create unlimited user accounts even when registration is disabled. Version 4.0.18 fixes the issue.

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

Affected products

thorsten · phpMyFAQ

Want to know if your infrastructure is exposed to this?

Talk to TrueHacking →

References

https://github.com/thorsten/phpMyFAQ/commit/f2ab673f0668753cd0f7c7c8bc7fd2304dcf5cb1 https://github.com/thorsten/phpMyFAQ/security/advisories/GHSA-w22q-m2fm-x9f4