Vulnerability · Published Aug 31, 2026 · Assigned by GitHub_M

CVE-2026-81889elFinder: SSRF protection bypass via DNS rebinding in the `fsock_get_contents()` fallback

High 8.6

In plain English

A high-severity server-side request forgery in elFinder from Studio-42. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.6High
Exploit odds (30 days)0.5%top 53.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

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 packages & fixed versions

EcosystemPackageFixed inAdvisory
Packagiststudio-42/elfinder2.1.70GHSA-8x3q-jpjh-qh5c

Affected products (as reported)

VendorProductVersions
Studio-42 elFinder < 2.1.70

Weakness: CWE-918 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

References