What’s Vulnerable › Vulnerabilities

CVE-2026-27836: phpMyFAQ Allows Unauthenticated Account Creation via WebAuthn Prepare Endpoint

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-02-27 · updated 2026-06-17
• Weakness: CWE-862

Description

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.

Affected products

• thorsten phpMyFAQ: before 4.0.18 — fixed in 4.0.18

How to fix

Upgrade to a fixed version: thorsten phpMyFAQ 4.0.18. Check the vendor advisory for mitigations.

References

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

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