phpMyFAQ vulnerability

phpMyFAQ 4.0.0 before 4.1.9 contains an authentication bypass vulnerability where WebAuthn registration endpoints attach credentials to any account without authentication or challenge validation. Attackers can stage a victim username, submit a forged fmt=none attestation to register a passkey, then log in bypassing passwords and TOTP for account takeover.

Published 17 Oct 2026Updated 17 Oct 20263 sources
CVSS 9.3

What happened

phpMyFAQ 4.0.0 before 4.1.9 contains an authentication bypass vulnerability where WebAuthn registration endpoints attach credentials to any account without authentication or challenge validation. Attackers can stage a victim username, submit a forged fmt=none attestation to register a passkey, then log in bypassing passwords and TOTP for account takeover.

Affected versions

phpMyFAQ: 4.0.0 through before 4.1.9 (semver) Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.