CVE-2026-12402 in OTP Login & Register WooCommerce Plugin
Summary
by MITRE • 09/19/2026
The OTP Login & Register Woocommerce plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'fb-config' Setting in all versions up to, and including, 2.7.3 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. On multisite installations where administrators do not hold the unfiltered_html capability, this vulnerability can be leveraged to target the network super administrator.
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Analysis
by VulDB Data Team • 09/19/2026
The OTP Login & Register plugin for WordPress presents a significant security risk due to a stored cross-site scripting (XSS) vulnerability located within the fb-config setting component. This flaw persists across all versions up to and including 2.7.3, stemming from insufficient input sanitization and output escaping mechanisms during data handling processes. The core technical deficiency lies in the application's failure to properly validate or encode user-supplied data before storing it in the database and subsequently rendering it on web pages without appropriate encoding. This architectural oversight allows malicious actors to inject arbitrary JavaScript code into persistent storage, which is then served to users upon page access, thereby facilitating client-side script execution within the context of the vulnerable website.
The operational impact of this vulnerability is severe due to its stored nature, meaning that once injected, the malicious payload remains active until manually removed from the database or configuration files. While exploitation typically requires authenticated attackers with administrator-level access and above, the persistence of the code amplifies the potential damage by affecting any user who views the compromised page. In standard single-site WordPress installations, this allows an attacker to steal session cookies, hijack administrative sessions, deface websites, or redirect users to malicious phishing sites. The attack vector relies on social engineering or privilege escalation if lower-level accounts are compromised and subsequently granted elevated privileges, highlighting the importance of strict role-based access control in mitigating such risks.
A critical aspect of this vulnerability is its potential impact on WordPress multisite installations where administrators lack the unfiltered_html capability. In these environments, standard administrative users are restricted from injecting raw HTML or JavaScript through typical content editors to prevent self-inflicted XSS attacks. However, because the fb-config setting does not enforce these restrictions during storage and retrieval, an administrator with limited privileges can bypass this safeguard by manipulating plugin settings directly. This specific configuration flaw enables such attackers to target network super administrators who may view dashboard elements or reports containing the injected script, effectively allowing privilege escalation from a restricted admin role to full control over the entire WordPress multisite network through client-side exploitation of the super administrator's browser session.
From an industry standards perspective, this vulnerability aligns with CWE-79: Improper Neutralization of Input During Web Page Generation, commonly known as Cross-site Scripting (XSS). The specific mechanism involves stored or persistent XSS where malicious scripts are saved on the target server and executed in victims' browsers upon request. In terms of attack tactics, this scenario maps to MITRE ATT&CK technique T1059: Command and Scripting Interpreter, specifically via browser-based execution such as JavaScript. It also relates to T1136: Create Account if new credentials are obtained through privilege escalation, or more accurately in the context of stored XSS leading to session hijacking, it falls under T1558: Steal Web Session Cookie, which is part of the Credential Access and Lateral Movement tactics within the ATT&CK framework.
To mitigate this vulnerability, immediate action should be taken by updating the OTP Login & Register plugin to a version newer than 2.7.3 where these sanitization issues have been addressed. Developers must implement rigorous input validation using WordPress functions such as sanitize_text_field for text inputs and esc_html or wp_kses_post for output escaping when rendering data in HTML contexts. For multisite environments, it is crucial to verify that all administrative interfaces enforce capability checks consistent with the unfiltered_html restriction unless explicitly required by core functionality. Security audits should routinely scan plugin code for missing escape functions before database writes and ensure that any dynamic content rendered from configuration settings undergoes proper encoding based on its context within the HTML document structure.