MFA bypass via empty-code comparison
Published Mar 17, 2026 · Updated Mar 17, 2026
Authentication bypass in TYPO3 E-Mail MFA Provider 1.0.5 and earlier and 2.0.0 allows remote authenticated users to bypass MFA. MailProvider::verify compares submitted input with a stored authentication code that can be empty, allowing an empty input to satisfy verification. Exploitation requires a nondefault E-Mail MFA Provider and another MFA provider available to the account, resulting in backend access as that account.
Summary
What happened
Authentication bypass in TYPO3 E-Mail MFA Provider 1.0.5 and earlier and 2.0.0 allows remote authenticated users to bypass MFA. MailProvider::verify compares submitted input with a stored authentication code that can be empty, allowing an empty input to satisfy verification. Exploitation requires a nondefault E-Mail MFA Provider and another MFA provider available to the account, resulting in backend access as that account.
The record
- CVE
- CVE-2026-4208
- Published
- Mar 17, 2026
- Updated
- Mar 17, 2026
- Vendor
- in2code GmbH
- Product
- E-Mail MFA Provider
- Classifications
- CWE-639, CWE-288, T1078
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 17, 2026CVE publishedPublication date reported by the CVE source.
- Mar 17, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=0 <=2.0.0
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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