---
id: CVE-2026-13447
title: >-
  The Mstore Api plugin for WordPress is vulnerable to Authentication Bypass via
  JWT Forgery in versions up to, and including, 4.20.0 This is due to missing
  cryptographic signature verification in the
  FirebasePhoneAuthHelper::verify_id_tok…
summary: >-
  The Mstore Api plugin for WordPress is vulnerable to Authentication Bypass via
  JWT Forgery in versions up to, and including, 4.20.0 This is due to missing
  cryptographic signature verification in the
  FirebasePhoneAuthHelper::verify_id_tok…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-287
published: '2026-09-05'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T13:12:58.310'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-13447'
references:
  - url: >-
      https://plugins.trac.wordpress.org/browser/mstore-api/tags/4.18.4/controllers/flutter-user.php#L829
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/mstore-api/tags/4.18.4/controllers/flutter-user.php#L940
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/mstore-api/tags/4.18.4/controllers/helpers/firebase-phone-auth-helper.php#L5
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/mstore-api/trunk/controllers/flutter-user.php#L829
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/mstore-api/trunk/controllers/flutter-user.php#L940
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/mstore-api/trunk/controllers/helpers/firebase-phone-auth-helper.php#L5
    label: security@wordfence.com
  - url: >-
      https://www.wordfence.com/threat-intel/vulnerabilities/id/4a1127af-74f6-4748-9aee-5a8c6c2766a4?source=cve
    label: security@wordfence.com
tags:
  - nvd
  - exploit-available
epss: 0.00447
epssPercentile: 0.36108
ingestedAt: '2026-09-06T02:48:39.255Z'
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/abraxas/CVE-2026-13447'
  checkedAt: '2026-09-25T08:20:50.015Z'
exploitAvailable: true
---

## Overview

The Mstore Api plugin for WordPress is vulnerable to Authentication Bypass via JWT Forgery in versions up to, and including, 4.20.0 This is due to missing cryptographic signature verification in the FirebasePhoneAuthHelper::verify_id_token() function, which decodes and validates Firebase ID token claims (alg, kid, aud, iss) but never calls openssl_verify() or any equivalent to validate the JWT signature against Google's actual public key certificates. This makes it possible for unauthenticated attackers to forge a Firebase Phone Auth JWT signed with a self-generated RSA key pair and impersonate any phone number, resulting in unauthorized access to existing WordPress accounts or creation of new arbitrary accounts.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.