OctoPrint provides a web interface for controlling consumer 3D printers. Prior to 1.11.8 and 2.0.0rc3, OctoPrint's custom Tornado upload handler and Flask with Werkzeug parse request parameters differently, allowing an attacker with FILE_UPLOAD permission to inject reserved internal upload fields through query parameters or parser differentials despite the earlier GHSA-m9jh-jf9h-x3h2 fix. The affected endpoints are /api/files/{local|sdcard}, /api/languages, /plugin/backup/restore, and /plugin/pluginmanager/upload_file. An attacker can make OctoPrint treat an arbitrary host file as a temporary upload, move it into a downloadable upload directory, disclose configuration secrets or other readable files, and remove runtime files in a way that can affect a later restart. This issue is fixed in versions 1.11.8 and 2.0.0rc3.

Affected: PyPI: OctoPrint

### Impact

OctoPrint versions up until and including 1.11.7 as well as 2.0.0rc1 and 2.0.0rc2 contain a vulnerability that allows an attacker with the `FILE_UPLOAD` permission to exfiltrate files from the host that OctoPrint has read access to, by moving them into the upload folder where they then can be downloaded from. This vulnerability was already reported as [GHSA-m9jh-jf9h-x3h2/CVE-2025-48067](https://github.com/OctoPrint/OctoPrint/security/advisories/GHSA-m9jh-jf9h-x3h2) but the fix provided in OctoPrint 1.11.2 turned out to be incomplete.

The primary risk lies in the potential exfiltration of secrets stored inside OctoPrint's config, or further system files. By removing important runtime files, this could also be used to impact the availability of the host after an attempted server restart. Given that the attacker requires a user account with file upload permissions, the actual impact of this should however hopefully be minimal in most cases.

### Patches

The vulnerability has been patched in version 1.11.8 and 2.0.0rc3.

### Details

OctoPrint's web application is implemented in Flask, but uploads are first intercepted by a custom upload handler built on Tornado that sits in front of it. The handler streams the upload to a temporary file on disk - so files larger than the available memory can be uploaded - and rewrites the request, adding internal form fields that tell Flask where to find that temporary file.

These fields are reserved and meant to be set only by…

Affected: PyPI: octoprint

### Impact

OctoPrint versions up until and including 1.11.7 as well as 2.0.0rc1 and 2.0.0rc2 contain a vulnerability that allows an attacker with the `FILE_UPLOAD` permission to exfiltrate files from the host that OctoPrint has read access to, by moving them into the upload folder where they then can be downloaded from. This vulnerability was already reported as [GHSA-m9jh-jf9h-x3h2/CVE-2025-48067](https://github.com/OctoPrint/OctoPrint/security/advisories/GHSA-m9jh-jf9h-x3h2) but the fix provided in OctoPrint 1.11.2 turned out to be incomplete.

The primary risk lies in the potential exfiltration of secrets stored inside OctoPrint's config, or further system files. By removing important runtime files, this could also be used to impact the availability of the host after an attempted server restart. Given that the attacker requires a user account with file upload permissions, the actual impact of this should however hopefully be minimal in most cases.

### Patches

The vulnerability has been patched in version 1.11.8 and 2.0.0rc3.

### Details

OctoPrint's web application is implemented in Flask, but uploads are first intercepted by a custom upload handler built on Tornado that sits in front of it. The handler streams the upload to a temporary file on disk - so files larger than the available memory can be uploaded - and rewrites the request, adding internal form fields that tell Flask where to find that temporary file.

These fields are reserved and meant to be set only by…