CVE-2026-0800 is a stored Cross-Site Scripting (XSS) vulnerability identified in the WordPress plugin 'User Submitted Posts – Enable Users to Submit Posts from the Front End' developed by specialk. This plugin allows users to submit posts from the front end of a WordPress site, including through custom fields. The vulnerability exists because the plugin fails to properly sanitize user input and escape output when rendering these custom fields on web pages. As a result, an unauthenticated attacker can inject arbitrary JavaScript code into posts that are stored persistently in the database. When any user visits a page containing the malicious post, the injected script executes in their browser context. This can lead to a range of attacks including theft of cookies or session tokens, defacement of website content, redirection to malicious sites, or execution of further malicious actions on behalf of the victim. The vulnerability affects all versions of the plugin up to and including version 20251210. The CVSS 3.1 base score is 7.2, reflecting a high severity due to network attack vector, no privileges or user interaction required, and a scope change indicating potential impact beyond the vulnerable component. Although no exploits have been reported in the wild yet, the ease of exploitation and the common usage of the plugin in WordPress installations make this a significant threat. The vulnerability is tracked under CWE-79, which covers improper neutralization of input during web page generation. The lack of available patches at the time of publication necessitates immediate attention from site administrators to mitigate risk.

For European organizations, this vulnerability poses a substantial risk to the confidentiality and integrity of web applications relying on the affected WordPress plugin. Exploitation could lead to unauthorized access to user credentials, session hijacking, and potential compromise of user accounts or administrative functions. This is particularly critical for organizations handling sensitive personal data under GDPR, as a breach could result in regulatory penalties and reputational damage. Additionally, attackers could deface websites or redirect visitors to malicious domains, undermining trust and causing business disruption. The vulnerability’s ability to be exploited remotely without authentication increases the attack surface significantly. Organizations with customer-facing websites, e-commerce platforms, or portals that allow user-generated content are especially vulnerable. The scope of impact extends beyond the plugin itself, as successful exploitation can affect all users visiting the compromised pages, potentially leading to widespread compromise within an organization’s user base or customer community.

Immediate mitigation involves monitoring for updates from the plugin developer and applying patches as soon as they become available. Until an official patch is released, organizations should implement strict input validation and output encoding on all user-submitted content, especially custom fields, to neutralize malicious scripts. Employing Web Application Firewalls (WAFs) with rules targeting common XSS payloads can provide temporary protection. Administrators should audit existing posts for suspicious scripts and remove any malicious content. Disabling or restricting the plugin’s functionality to trusted users only can reduce exposure. Additionally, enforcing Content Security Policy (CSP) headers can limit the impact of injected scripts by restricting the sources from which scripts can be loaded. Regular security scanning and penetration testing focused on XSS vulnerabilities will help detect exploitation attempts. Finally, educating content managers and users about the risks of XSS and safe content submission practices can reduce inadvertent exposure.