Auth bypass in Inspireui Mstore API – Create Native Android & iOS Apps On The Cloud

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, 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.

Vulnerability class: Broken Authentication

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (37.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 37.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-13447: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.001

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-13447?
CVE-2026-13447 is a critical-severity vulnerability in Inspireui Mstore API – Create Native Android & iOS Apps On The Cloud, classified under Improper Authentication. CVSS score: 9.8/10. Published 2026-09-05.
How severe is CVE-2026-13447?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2026-13447 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.