Vulnerability in Thorsten Phpmyfaq
CVE-2026-85590
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.
Published · last modified .
EPSS exploit prediction
EPSS: 0.005 (42.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 42.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/thorsten/phpMyFAQ/security/advisories/GHSA-h96g-59xp-7r5m (vendor-advisory)
- www.vulncheck.com/advisories/phpmyfaq-before-4.1.8-authentication-bypass-via-tw… (third-party-advisory)