Vulnerability · Published Sep 4, 2026 · Assigned by VulnCheck

CVE-2026-85590phpMyFAQ before 4.1.8 Authentication Bypass via Two-Factor Disable

High 7.1

In plain English

A high-severity security flaw in phpMyFAQ from thorsten. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 44% of all known vulnerabilities).

Severity (CVSS 4.0)7.1High

Exploit odds (30 days)0.5%top 55.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
thorsten	phpMyFAQ	0 – before 4.1.8

Weakness: CWE-308 · 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

References

GitHub Security Advisory (GHSA-h96g-59xp-7r5m) vendor-advisory
VulnCheck Advisory: phpMyFAQ before 4.1.8 Authentication Bypass via Two-Factor Disable third-party-advisory