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Mstore Api - Security Vulnerability (CVE-2026-13447)

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.

CVE-2026-13447

CRITICAL CVSS 9.8 Published 2026-09-05 Updated 2026-09-08
AI Risk Critical (100/100) Active Exploit: No strong signal Published Exploit: No public exploit references Priority: P1 Immediate
Severity Band CRITICAL
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected Components 2
Reference Links 7
AI Risk Engine Critical (100/100)
Exploitability Very High
Active Exploitation No strong signal
Published Exploit Status No public exploit references

Threat Timeline

  1. 2026-09-05 CVE published and first recorded in the threat feed.
  2. 2026-09-08 Record updated with latest vulnerability metadata.
  3. 2026-09-06 AI technical context refreshed for mitigation and impact guidance.
  4. Now Monitoring for follow-up changes, linked references, and new related CVEs.

AI Context

Machine-generated threat intelligence

AI Updated 3 days ago

AI enriched 3 days ago (2026-09-06 09:08 UTC)

Technical 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_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…

Potential Impact

Severity is CRITICAL (CVSS 9.8). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.

Exploitability Assessment

Exploitability is assessed as Very High based on remote code execution potential, low-bar exploit prerequisites.

Primary risk drivers: remote code execution potential, low-bar exploit prerequisites

Mitigation Recommendations

Validate affected product versions, prioritize patching, and monitor references for vendor remediation guidance. If immediate patching is not possible, apply compensating controls and limit exposure of vulnerable surfaces.

Detection & Monitoring

Track authentication anomalies, unexpected file writes, and suspicious plugin API activity around affected components.

Business Impact Lens

AI risk score 100/100 (Critical, Very High) with priority P1 Immediate. Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.

References

What to do about this

Patch immediately Serious, and reachable without meaningful privilege.

Fix it

Update Mstore Api to the latest available version.

Where the vendor has not published a fix yet, disable the plugin until they do.

Cannot update today? Administrator multi-factor authentication in Hack Halt Pro blocks this class of attack before WordPress processes the request.

Require a second factor for every administrator account. This is the single highest-value control against credential stuffing and reused passwords, because a valid password alone stops being enough.

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Not sure if you are affected?

Scan your site to see whether it runs Mstore Api, and at which version.

Free, no installation, no account. It reads what your site already publishes, then tells you which plugins carry known vulnerabilities and what to do about each one.

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Am I affected by this vulnerability?

You are affected if your site runs Mstore Api. No account is needed to exploit this, so a public site is reachable by anyone.

How do I fix it?

Update Mstore Api to the latest available version. Where the vendor has not yet published a fix, remove or disable the plugin until they do. Until you can update, Administrator multi-factor authentication in Hack Halt Pro contains this class of attack at the request layer.

What can an attacker actually do?

This is a Authentication Bypass flaw. An attacker who exploits it can sign in as another user, frequently an administrator, without a password.