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.
History

Fri, 04 Sep 2026 11:45:00 +0000

Type Values Removed Values Added
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.
Title phpMyFAQ before 4.1.8 Authentication Bypass via Two-Factor Disable
First Time appeared Phpmyfaq
Phpmyfaq phpmyfaq
Weaknesses CWE-308
CPEs cpe:2.3:a:phpmyfaq:phpmyfaq:*:*:*:*:*:*:*:*
Vendors & Products Phpmyfaq
Phpmyfaq phpmyfaq
References
Metrics cvssV4_0

{'score': 7.1, '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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2026-09-04T11:29:56.063Z

Updated: 2026-09-04T11:29:56.063Z

Reserved: 2026-09-04T10:59:00.162Z

Link: CVE-2026-85590

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-04T12:17:21.327

Modified: 2026-09-04T12:17:21.327

Link: CVE-2026-85590

cve-icon Redhat

No data.