# CVE-2026-85590

## Summary

- **CVE ID:** CVE-2026-85590
- **Severity:** HIGH
- **CVSS Score:** 7.1 (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)
- **CWE:** CWE-308
- **Published:** Sep 4, 2026
- **Last Modified:** Sep 4, 2026

## 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

- thorsten — phpMyFAQ (0)
- thorsten — phpMyFAQ (4.1.8)

## References

- [CNA](https://github.com/thorsten/phpMyFAQ/security/advisories/GHSA-h96g-59xp-7r5m)
- [CNA](https://www.vulncheck.com/advisories/phpmyfaq-before-4.1.8-authentication-bypass-via-two-factor-disable)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.39%
- **EPSS Percentile:** 31.8

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._