CVE-2026-73351 in Social Login and Register Plugin
Summary
by MITRE • 08/18/2026
Unauthenticated Cross Site Scripting (XSS) in WordPress Social Login and Register <= 7.8.1 versions.
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Analysis
by VulDB Data Team • 08/18/2026
The vulnerability identified as an unauthenticated cross-site scripting flaw within the WordPress Social Login and Register plugin, specifically affecting versions up to 7.8.1, represents a significant security risk for websites relying on this software to manage user authentication via third-party social media providers. This type of attack allows malicious actors to inject client-side scripts into web pages viewed by other users without requiring any form of prior authentication or login credentials. The presence of such a flaw indicates that the application fails to adequately sanitize or validate input data before processing it, thereby allowing attackers to bypass standard security controls and execute arbitrary JavaScript code in the context of the victim's browser session.
From a technical perspective, cross-site scripting vulnerabilities typically arise when web applications incorporate untrusted data into their output without proper encoding or validation. In the case of this specific plugin, the flaw likely exists within one of the endpoints responsible for handling social login redirects, registration forms, or profile updates where user-supplied input is reflected back to the browser. When a victim interacts with a crafted link or form submission containing malicious script payloads, the browser interprets these scripts as legitimate content from the trusted domain hosting the WordPress site. This execution context grants the injected code full access to cookies, session tokens, and other sensitive information stored locally by the browser for that specific origin.
The operational impact of this vulnerability is severe due to its unauthenticated nature. Attackers do not need valid user accounts or administrative privileges to exploit the flaw, which significantly lowers the barrier to entry for potential adversaries. Successful exploitation can lead to session hijacking, where an attacker steals a victim's authentication cookies and impersonates them within the application. This could allow unauthorized access to personal data, account settings, or even administrative functions if the targeted user holds elevated privileges. Furthermore, attackers may use this vector to deface websites by altering displayed content, redirect users to phishing sites designed to steal credentials from other platforms, or distribute malware through drive-by download techniques that exploit browser vulnerabilities triggered by the injected scripts.
This vulnerability aligns with Common Weakness Enumeration (CWE) category CWE-79, which describes Improper Neutralization of Input During Web Page Generation commonly known as Cross-site Scripting. The lack of input validation and output encoding is a fundamental design flaw that violates secure coding principles essential for web application security. By failing to treat user input as potentially hostile data, the plugin exposes users to risks associated with client-side code injection, undermining the integrity and confidentiality of the authentication system it was designed to enhance.
To mitigate this risk, immediate action is required from website administrators using affected versions of the Social Login and Register plugin. The primary remediation step involves upgrading the plugin to version 7.8.2 or any later release where these input validation issues have been addressed by the developers. If an upgrade is not immediately feasible, temporary mitigations should include implementing a Web Application Firewall (WAF) configured with rulesets capable of detecting and blocking common XSS payloads in HTTP requests. Additionally, enabling Content Security Policy headers can help restrict the sources from which scripts are allowed to execute, thereby reducing the impact even if some injection attempts succeed. Regular security audits and code reviews focusing on input sanitization practices are also recommended to prevent similar vulnerabilities in future updates or custom integrations within the WordPress ecosystem.