CVE-2026-85590 PUBLISHED

phpMyFAQ before 4.1.8 Authentication Bypass via Two-Factor Disable

Assigner: VulnCheck
Reserved: 04.09.2026 Published: 04.09.2026 Updated: 04.09.2026

phpMyFAQ before 4.1.8 contains an authentication bypass vulnerability in its two-factor authentication (TOTP) disable functionality. The removeTwofactorConfig() handler (reachable via POST /api/user/remove-twofactor) verifies only that the user is logged in and that a valid CSRF token is supplied, then disables TOTP without requiring password re-entry or a current TOTP code. The same downgrade is also reachable inline via PUT /api/user/data/update, which accepts a plain twofactor_enabled form field under the same session+CSRF-only guard. An attacker who has hijacked a user's session can silently strip two-factor protection from any account, including administrator accounts, after which password-only authentication succeeds.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
CVSS Score: 7.1

Product Status

Vendor thorsten
Product phpMyFAQ
Versions Default: unaffected
  • affected from 0 to 4.1.8 (excl.)
  • Version 4.1.8 is unaffected

Credits

  • skeletonsec reporter

References

Problem Types

  • Use of Single-factor Authentication CWE