# CVE-2026-61900: jDownloads Joomla extension unauthenticated file upload in upload-handler.php

Source: https://junglewise.ai/threats/cve-2026-61900-jdownloads-joomla-extension-unauthenticated-file-upload-in-upload  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-20. Updated: 2026-07-20  
License: CC BY 4.0 with a link back

CVE-2026-61900 · Severity: info · CVSS 10 · Published 2026-07-20

jDownloads, a popular file management extension for the Joomla website platform, contained a security flaw that allowed anyone on the internet to upload files to a web server without logging in. This occurred because a testing script was accidentally included in several software releases. An attacker could use this to host malicious content on the site, fill up server storage, or potentially take full control of the website if the server is configured to run certain types of uploaded files.

Technologies: [jDownloads](https://junglewise.ai/threats/technologies/jdownloads). Vendors: [jDownloads](https://junglewise.ai/threats/vendors/jdownloads).

## Quick answers

**Is CVE-2026-61900 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-61900 being exploited in the wild.

**How severe is CVE-2026-61900?** Informational severity, with a CVSS score of 10, published 20 July 2026.

**Which products and versions are affected?** jDownloads 4.1.0 - 4.1.5.

**Is there a fix for CVE-2026-61900?** A patch was published on 2026-07-18: jDownloads version 4.1.6 released to remove the vulnerable script. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-61900 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-61900?** Check whether you run jDownloads at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A standalone test script, 'upload-handler.php', was inadvertently included in the jDownloads 4.1.x branch. This script lacks essential security checks, including the Joomla '_JEXEC' guard, session validation, CSRF tokens, and permission checks. While the script contains a hardcoded allow-list that excludes '.php' files, it permits the upload of archives, documents, and executables (e.g., .exe, .msi). An attacker can achieve Remote Code Execution (RCE) if the server is misconfigured to execute secondary extensions (e.g., .php.jpg) or if the attacker can leverage the uploaded files in combination with other vulnerabilities. The vulnerability is resolved in version 4.1.6, which removes the offending file and associated test directories.

## Affected products

- jDownloads jDownloads extension for Joomla 4.1.0 - 4.1.5

## Timeline

- 2026-07-16: disclosed: Vulnerability reported privately to the developer.
- 2026-07-18: patched: jDownloads version 4.1.6 released to remove the vulnerable script.
- 2026-07-20: advisory: CVE-2026-61900 published.

## References

- [https://mysites.guru/blog/jdownloads-4-1-unauthenticated-upload-flaw/](https://mysites.guru/blog/jdownloads-4-1-unauthenticated-upload-flaw/)
- [https://www.jdownloads.com/](https://www.jdownloads.com/)

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