inspireui MStore API Plugin up to 4.20.0 on WordPress verify_id_token improper authentication

Summaryinfo

A vulnerability identified as critical has been detected in inspireui MStore API Plugin up to 4.20.0. The impacted element is the function FirebasePhoneAuthHelper::verify_id_token. Performing a manipulation results in improper authentication. This vulnerability is cataloged as CVE-2026-13447. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in inspireui MStore API Plugin up to 4.20.0. It has been classified as critical. This affects the function FirebasePhoneAuthHelper::verify_id_token. The manipulation with an unknown input leads to a improper authentication vulnerability. CWE is classifying the issue as CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at wordfence.com. This vulnerability is uniquely identified as CVE-2026-13447 since 06/26/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/05/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• WordPress Plugin

Vendor

• inspireui

Name

• MStore API Plugin

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 4.10
• 4.11
• 4.12
• 4.13
• 4.14
• 4.15
• 4.16
• 4.17
• 4.18
• 4.19
• 4.20.0

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

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• 🔒

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