CVE-2026-13447
Received Received - Intake

Authentication Bypass via JWT Forgery in Mstore Api WordPress Plugin

Publication date: 2026-09-05

Last updated on: 2026-09-05

Assigner: Wordfence

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.

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Meta Information

Published
2026-09-05
Last Modified
2026-09-05
Generated
2026-09-05
AI Q&A
2026-09-05
EPSS Evaluated
N/A
NVD
CVE-2026-13447
EUVD
EUVD-2026-71838

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
mstore api_plugin to 4.20.0 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-287 When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

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Executive Summary

The Mstore Api plugin for WordPress has an authentication bypass flaw in versions up to 4.20.0. It fails to verify JWT signatures properly in the FirebasePhoneAuthHelper::verify_id_token() function. Attackers can forge Firebase Phone Auth JWTs using self-generated RSA keys to impersonate any phone number, gaining unauthorized access to existing accounts or creating new ones.

Detection Guidance

Check WordPress plugins for Mstore Api versions up to 4.20.0. Review logs for unusual authentication attempts or account creations. No specific commands are provided in the context.

Impact Analysis

Unauthenticated attackers could exploit this to take over WordPress accounts, create fake accounts, or gain elevated privileges. Since it affects authentication, it may lead to data breaches, unauthorized transactions, or full site compromise if the plugin is widely used.

Compliance Impact

This vulnerability could lead to unauthorized access to user data, violating GDPR's data protection requirements and HIPAA's safeguards for protected health information. Organizations may face fines or legal penalties for failing to secure user data adequately.

Mitigation Strategies

Update the Mstore Api plugin to the latest version beyond 4.20.0. Disable Firebase Phone Auth if not required. Monitor for unauthorized access or account changes.

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