CVE-2026-4208: Ralffreit/mfa email Authentication Bypass Vulnerability

HIGH
Advisory Identifier: GHSA-29r8-gvx4-r9w3
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CVSS 8.8
CWE-639
Published
Advisory Summary

CVE-2026-4208 is a HIGH (CVSS 8.8) authentication bypass vulnerability (CWE-639: Authorization Bypass Through User-Controlled Key) affecting Ralffreit/mfa email libraries in the Packagist ecosystem. The issue involves authentication bypass in extension "e-mail mfa provider" (mfa_email). Remediation is available by upgrading affected packages to version 1.0.7, 2.0.1.

CVE-2026-4208 at a Glance

CVE Identifier CVE-2026-4208
GHSA Identifier GHSA-29r8-gvx4-r9w3
Severity HIGH
CVSS v3.1 Base Score 8.8
CWE Classification CWE-639: Authorization Bypass Through User-Controlled Key
Affected Product Ralffreit/mfa email
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 8.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-4208

To remediate this vulnerability, upgrade all affected Ralffreit/mfa email dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

ralffreit/mfa-email fixed: 1.0.7 
Upgrade ralffreit/mfa-email to 1.0.7
ralffreit/mfa-email fixed: 2.0.1 
Upgrade ralffreit/mfa-email to 2.0.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for ralffreit/mfa-email

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-4208, inspect your project dependencies for Ralffreit/mfa email:

inspect dependencies for ralffreit/mfa-email

Analyze the terminal output to locate any version of Ralffreit/mfa email in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.0.7), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-639: Authorization Bypass Through User-Controlled Key, where the system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. In Ralffreit/mfa email, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2026-4208 Affected Ralffreit/mfa email Versions

2 component(s)
Fixed Versions:
1.0.72.0.1
Product / Package Ecosystem Affected Versions Fixed Version
ralffreit/mfa-email
 Packagist
< 1.0.7
1.0.7
ralffreit/mfa-email
 Packagist
≥ 2.0.0
< 2.0.1
All 1 versions
2.0.0
2.0.1

References

NVD — CVE-2026-4208 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-4208
Security Fix Commit FIX COMMIT
https://github.com/MrSilaz/mfa_email/commit/0bb7e85b236a5232f7b092915453dd7c3da48f12
Ralffreit/mfa email Source Repository REPOSITORY
https://github.com/MrSilaz/mfa_email
Ralffreit/mfa email Release RELEASE
https://github.com/MrSilaz/mfa_email/releases/tag/v1.0.7
Ralffreit/mfa email Release RELEASE
https://github.com/MrSilaz/mfa_email/releases/tag/v2.0.1
Ralffreit/mfa email Security Information SECURITY
https://typo3.org/security/advisory/typo3-ext-sa-2026-007

Frequently Asked Questions

What is CVE-2026-4208?
CVE-2026-4208 is a security vulnerability in Ralffreit/mfa email involving Authentication Bypass in extension "E-Mail MFA Provider" (mfa_email) under CWE-639: Authorization Bypass Through User-Controlled Key.
Which Ralffreit/mfa email versions are affected?
Affected versions include releases prior to 1.0.7, 2.0.1 across affected packages: ralffreit/mfa-email.
What version fixes CVE-2026-4208?
Upgrading to 1.0.7, 2.0.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is ralffreit/mfa-email affected?
Yes, ralffreit/mfa-email is affected in releases prior to 1.0.7, 2.0.1. Upgrade your dependency to 1.0.7, 2.0.1 or later.
What is the CVSS score of CVE-2026-4208?
CVE-2026-4208 has a CVSS v3.1 base score of 8.8 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-4208?
CVE-2026-4208 is classified under CWE-639: Authorization Bypass Through User-Controlled Key (The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.).
How can I check Packagist dependencies for CVE-2026-4208?
Run the dependency tree command: 'inspect dependencies for ralffreit/mfa-email'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-29r8-gvx4-r9w3",
  "modified" : "2026-04-27T16:45:42Z",
  "published" : "2026-03-17T09:31:28Z",
  "aliases" : [ "CVE-2026-4208" ],
  "summary" : "Authentication Bypass in extension \"E-Mail MFA Provider\" (mfa_email)",
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "ralffreit/mfa-email"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.0.7"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "ralffreit/mfa-email"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.0.0"
      }, {
        "fixed" : "2.0.1"
      } ]
    } ],
    "versions" : [ "2.0.0" ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-4208"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/MrSilaz/mfa_email/commit/0bb7e85b236a5232f7b092915453dd7c3da48f12"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/MrSilaz/mfa_email"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/MrSilaz/mfa_email/releases/tag/v1.0.7"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/MrSilaz/mfa_email/releases/tag/v2.0.1"
  }, {
    "type" : "WEB",
    "url" : "https://typo3.org/security/advisory/typo3-ext-sa-2026-007"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-639" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-18T16:17:23Z",
    "nvd_published_at" : "2026-03-17T09:16:14Z"
  }
}