CVE-2026-85590 json
phpMyFAQ before 4.1.8 Authentication Bypass via Two-Factor Disable
published 2026-09-04 2 mo ago modified 2026-09-08 2 mo ago also EUVD-2026-71013
- cvss
- 7.1
- version 4.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 44%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- thorsten phpMyFAQ 4.1.8
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
0.52% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/thorsten/phpMyFAQ/security/advisories/GHSA-h96g-59xp-7r5m referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 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 |
| CNA | 4.0 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- thorsten phpMyFAQ
Classification
- Weakness
-
- CWE-308 Use of Single-factor Authentication
References
-
github.com
/thorsten/phpMyFAQ/security/advisories/GHSA-h96g-59xp-7r5m
vendor-advisory, exploit
-
vulncheck.com
/advisories/phpmyfaq-before-4.1.8-authentication-bypass-via-two-factor-disable
third-party-advisory
Sources
- CVE List CVE-2026-85590
- NVD CVE-2026-85590
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