CVE-2026-2383 is a stored Cross-Site Scripting (XSS) vulnerability identified in the Simple Download Monitor plugin for WordPress, versions up to and including 4.0.5. The root cause is insufficient sanitization and escaping of input in custom fields during web page generation, categorized under CWE-79. Authenticated attackers with Contributor-level privileges or higher can exploit this flaw by injecting arbitrary JavaScript code into custom fields. Once injected, the malicious script executes in the context of any user who views the compromised page, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the user. The vulnerability has a CVSS v3.1 base score of 6.4, reflecting medium severity, with an attack vector of network, low attack complexity, requiring privileges but no user interaction, and impacting confidentiality and integrity with no effect on availability. The scope is changed as the vulnerability affects components beyond the attacker’s privileges. No public exploits have been reported yet. The plugin is widely used in WordPress environments for managing downloadable content, making this an important vulnerability for website administrators to address promptly.

The impact of CVE-2026-2383 is significant for organizations relying on the Simple Download Monitor plugin within their WordPress sites. Exploitation allows attackers with relatively low privileges (Contributor-level) to inject persistent malicious scripts, which execute in the browsers of site visitors and administrators. This can lead to theft of sensitive information such as authentication cookies, personal data, or administrative credentials, enabling further compromise of the website or user accounts. Additionally, attackers could perform unauthorized actions on behalf of users, potentially leading to data manipulation or defacement. The vulnerability undermines the confidentiality and integrity of the affected systems but does not impact availability. Given WordPress’s extensive global use, especially among small to medium enterprises and content creators, the risk of widespread exploitation exists if the vulnerability is not mitigated. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the potential for future attacks.

To mitigate CVE-2026-2383, organizations should immediately update the Simple Download Monitor plugin to a version that addresses this vulnerability once released by the vendor. In the absence of an official patch, administrators can implement strict input validation and output encoding for all custom fields within the plugin, ensuring that any user-supplied data is sanitized to neutralize script tags and other executable content. Restricting Contributor-level user permissions or auditing user roles to limit who can add or modify custom fields can reduce the attack surface. Employing Web Application Firewalls (WAFs) with custom rules to detect and block suspicious script injections targeting the plugin’s input fields can provide additional protection. Regularly monitoring website logs for unusual activities and conducting security assessments focused on plugin vulnerabilities will help detect exploitation attempts early. Finally, educating users about the risks of XSS and maintaining a robust backup strategy will aid in recovery if compromise occurs.