CVE-2026-13447
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,…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.38%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.38% probability · 31th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-287
- Source
- security@wordfence.com
References
- https://plugins.trac.wordpress.org/browser/mstore-api/tags/4.18.4/controllers/flutter-user.php#L829
- https://plugins.trac.wordpress.org/browser/mstore-api/tags/4.18.4/controllers/flutter-user.php#L940
- https://plugins.trac.wordpress.org/browser/mstore-api/tags/4.18.4/controllers/helpers/firebase-phone-auth-helper.php#L5
- https://plugins.trac.wordpress.org/browser/mstore-api/trunk/controllers/flutter-user.php#L829
- https://plugins.trac.wordpress.org/browser/mstore-api/trunk/controllers/flutter-user.php#L940
- https://plugins.trac.wordpress.org/browser/mstore-api/trunk/controllers/helpers/firebase-phone-auth-helper.php#L5
- https://www.wordfence.com/threat-intel/vulnerabilities/id/4a1127af-74f6-4748-9aee-5a8c6c2766a4?source=cve
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.