CVE-2026-85590

What it is

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.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of data tampering.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-09-04 12:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-08 20:05 UTC Last updatedMost recent change to the record

Details

Published

2026-09-04 12:17 UTC

Last modified

2026-09-08 20:05 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-308

Record status

Deferred

Attack profile CVSS 4.0 · 7.1

Attack vector

Network

Complexity

Low

Attack requirements

None

Privileges needed

Low

User interaction

None

Confidentiality

None

Integrity

High

Availability

None