An unauthenticated reflected cross-site scripting vulnerability in the query handling of CMSimpleXH allows remote attackers to inject and execute arbitrary JavaScript in a victim's browser via a crafted request (e.g., a maliciously crafted POST login). Successful exploitation may lead to theft of session cookies, credential disclosure, or other client-side impacts.
A reflected XSS vulnerability exists in CMSimple_XH 1.8's index.php router when attacker-controlled path segments are not sanitized or encoded before being inserted into the generated HTML (navigation links, breadcrumbs, search form action, footer links). An attacker-controlled string placed in the URL path is reflected into multiple HTML elements, allowing execution of arbitrary JavaScript in victims' browsers visiting a crafted URL.
CMSimple_XH 1.7.4 is affected by a remote code execution (RCE) vulnerability. To exploit this vulnerability, an attacker must use the "File" parameter to upload a PHP payload to get a reverse shell from the vulnerable host.