Vulnerability · Published Sep 5, 2026 · Assigned by Wordfence

CVE-2026-13447MStore API <= 4.20.0 - Unauthenticated Authentication Bypass via 'id_token' Parameter JWT Forgery

Critical 9.8

In plain English

A critical-severity improper authentication in MStore API – Create Native Android & iOS Apps On The Cloud from inspireui. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 53% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.

Severity (CVSS 3.1)9.8Critical

Exploit odds (30 days)0.7%top 47.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack tooling1Public PoC

Official 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.

Affected products (as reported)

Vendor	Product	Versions
inspireui	MStore API – Create Native Android & iOS Apps On The Cloud	0 – through 4.20.0

Weakness: CWE-287 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

In plain English

Official description

Affected products (as reported)

References