CVE-2026-81889: Studio-42 Elfinder

High severity, CVSS 8.6. EPSS: 0.6% chance of exploitation in the next 30 days.

elFinder is an open-source file manager for web, written in JavaScript using jQuery UI. Prior to 2.1.70, elFinder URL uploads in php/elFinder.class.php can bypass server-side request forgery protections when PHP cURL is unavailable because validate_address() validates $info['ip'], but get_remote_contents() selects fsock_get_contents(), which connects to $arr['host'] and performs a second DNS resolution. An attacker able to submit a URL upload can use DNS rebinding to have the first resolution return a public address and the connection resolution return a loopback or private address, causing the internal HTTP response body to be stored as an uploaded file and made readable through elFinder. After a successful fetch, get_headers($url, true) separately requests the original hostname without reusing the validated and pinned connection, creating an additional blind server-side request forgery path even when curl_get_contents() is selected. This issue is fixed in version 2.1.70.

Affected products

• Studio-42 Elfinder: before 2.1.70 (fixed in 2.1.70)

Published 2026-08-31. Last modified 2026-09-09.