CVE-2026-84818 in Open User Map Plugin
Summary
by MITRE • 09/08/2026
Unauthenticated Cross Site Scripting (XSS) in Open User Map <= 1.4.50 versions.
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Analysis
by VulDB Data Team • 09/08/2026
The vulnerability identified as an unauthenticated cross-site scripting flaw within the Open User Map plugin, specifically affecting versions up to and including 1.4.50, represents a significant security risk for WordPress-based websites that utilize this functionality. This type of attack allows malicious actors to inject client-side scripts into web pages viewed by other users without requiring any form of authentication or prior login credentials. The core technical flaw typically stems from insufficient input validation and output encoding mechanisms within the plugin's codebase when processing user-supplied data. In many instances, such vulnerabilities arise because the application directly echoes back user inputs—such as map coordinates, location descriptions, or custom markers—to the browser without sanitizing special characters like angle brackets, quotes, or ampersands that are essential for constructing HTML and JavaScript payloads. This lack of proper encoding enables an attacker to break out of the expected data context and execute arbitrary scripts in the victim's web browser under the security context of the affected website.
From a technical perspective, this vulnerability aligns with Common Weakness Enumeration category CWE-79, which is formally defined as Improper Neutralization of Input During Web Page Generation commonly known as Cross-site Scripting. The absence of authentication for this specific vector means that any internet user can trigger the exploit by simply visiting a crafted URL or interacting with a compromised page element, rather than needing to be an authenticated administrator or editor on the WordPress site. This lowers the barrier to entry significantly for attackers and increases the likelihood of successful exploitation in automated campaigns. The attack payload often involves embedding JavaScript code that interacts with the Document Object Model (DOM) to perform actions such as stealing session cookies, capturing keystrokes, performing actions on behalf of the victim, or redirecting users to malicious phishing sites designed to harvest credentials.
The operational impact of this vulnerability is severe due to its potential for widespread data theft and site defacement. Since cross-site scripting attacks are executed in the context of the trusted website, victims trust the content served by the domain. An attacker can exploit this trust to steal sensitive information such as administrative session tokens, which could lead to full compromise of the WordPress installation if combined with other vulnerabilities or through social engineering tactics that trick users into revealing their credentials on a phishing page hosted by the attacker. Furthermore, persistent XSS variants stored within the map data could affect multiple visitors over time, turning the website into a vector for distributing malware or conducting large-scale credential harvesting operations against unsuspecting site visitors and administrators alike.
To mitigate this risk, immediate action is required to update the Open User Map plugin to version 1.4.51 or later where these input validation issues have been addressed by the developers. It is crucial to ensure that all plugins are kept up to date with security patches released by their respective maintainers. In addition to updating software, implementing a Web Application Firewall can provide an additional layer of defense by filtering out malicious HTTP requests containing known XSS patterns before they reach the application logic. Security best practices also dictate employing Content Security Policy headers to restrict the sources from which scripts can be loaded and executed, thereby limiting the impact even if an injection attempt succeeds. Regular security audits and code reviews focusing on input sanitization and output encoding are essential for maintaining a robust defense posture against such client-side attacks.