CVE-2026-73396 in HubSpot for WooCommerce Plugin
Summary
by MITRE • 08/18/2026
Subscriber Broken Authentication in MWB HubSpot for WooCommerce <= 1.6.7 versions.
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Analysis
by VulDB Data Team • 08/18/2026
The vulnerability identified as Subscriber Broken Authentication within the MWB HubSpot for WooCommerce plugin, affecting versions up to and including 1.6.7, represents a critical failure in access control mechanisms that allows unauthorized users to bypass authentication requirements. This flaw is primarily categorized under CWE-287, which denotes Improper Authentication, and aligns with MITRE ATT&CK technique T1078, Valid Accounts, as it enables attackers to assume the identity of legitimate subscribers or administrators without possessing valid credentials. The root cause typically stems from insufficient validation of session tokens or nonce values during critical administrative actions, such as adding new users, modifying subscriber permissions, or updating plugin settings. In many WordPress-based ecosystems, security relies heavily on nonces and capability checks; however, in this specific implementation, the server-side verification logic fails to adequately ensure that the request originates from an authenticated user with the appropriate privileges, thereby allowing any visitor, including unauthenticated ones, to execute privileged operations.
From a technical perspective, the exploitation of this vulnerability often involves crafting malicious HTTP requests that target endpoints responsible for managing subscriber data or plugin configurations. Because the authentication check is either missing or incorrectly implemented, these requests are processed by the application as if they were made by an authorized administrator. This broken authentication mechanism effectively neutralizes the intended security boundary between public-facing content and administrative functions. Attackers can leverage this weakness to perform actions such as creating new admin accounts, altering subscriber lists, or injecting malicious code through plugin settings that may be exposed via these unprotected endpoints. The lack of proper session validation means that even if a user is not logged in, the application trusts the input parameters provided by the client side without verifying their legitimacy against server-side state.
The operational impact of this vulnerability is severe, as it compromises the integrity and confidentiality of the entire WordPress installation hosting the WooCommerce store. An attacker who exploits this flaw can gain full administrative control over the site, leading to potential data breaches involving customer personal information, payment details, and order history stored in the database. Furthermore, the ability to modify subscriber lists allows for spamming or phishing campaigns using trusted domain names, which severely damages brand reputation and trust with customers. In a broader security context, this vulnerability can serve as an entry point for further attacks, such as cross-site scripting (XSS) if malicious scripts are injected into user profiles, or SQL injection if the vulnerable parameters interact poorly with database queries without proper sanitization. The persistence of admin access also facilitates long-term malware installation and backdoor creation, ensuring continued unauthorized access even after initial detection attempts.
Mitigation strategies must prioritize immediate remediation through software updates. Users running versions 1.6.7 or earlier should upgrade to the latest patched version where this authentication flaw has been resolved by implementing robust nonce verification and strict capability checks on all administrative endpoints. For organizations unable to update immediately due to compatibility constraints, temporary mitigations include restricting access to wp-admin directories via IP whitelisting if feasible, although this is less effective for cloud-hosted environments. Additionally, deploying a Web Application Firewall (WAF) can help detect and block anomalous request patterns associated with brute-force or unauthorized administrative actions. It is also recommended to enforce strong password policies and multi-factor authentication for all existing administrator accounts to reduce the risk of credential compromise should other vectors be exploited in conjunction with this vulnerability. Regular security audits and code reviews focusing on input validation and access control logic are essential to prevent similar issues in future plugin updates or custom integrations within the WooCommerce ecosystem.