TYPO3-EXT-SA-2026-007: Authentication Bypass in extension "E-Mail MFA Provider" (mfa_email)

• Release Date: March 17, 2026
• Component Type: Third party extension. This extension is not a part of the TYPO3 default installation.
• Component: "E-Mail MFA Provider" (mfa_email)
• Composer Package Name: ralffreit/mfa-email
• Vulnerability Type: Authentication Bypass
• Affected Versions: 2.0.0 and below
• Severity: High
• Suggested CVSS v4.0: AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
• References: CVE-2026-4208, CWE-288

Problem Description

The extension fails to properly reset the generated MFA code after successful authentication. This leads to a possible MFA bypass for future login attempts by providing an empty string as MFA code to the extensions MFA provider.

The vulnerability is only exploitable, when the “E-Mail MFA Provider” is not the default MFA provider and when at least one other MFA provider is available to the user.

Solution

All versions of this extension that are known to be vulnerable will no longer be available for download from the TYPO3 Extension Repository. The extension author failed in providing a security fix for the reported vulnerability in a decent amount of time.

Please uninstall and delete the extension folder from your installation and search on the TYPO3 Extension Repository for alternative extensions.

Credits

Thanks to Jan Holtkötter for reporting the vulnerability.

General Advice

Follow the recommendations that are given in the TYPO3 Security Guide. Please subscribe to the typo3-announce mailing list.