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OpenAdvisories
High · 7.0 CVE-2026-54134 EUVD-2026-64044GHSA-j4h9-pm27-4rfwPYSEC-2026-2687

OctoPrint: File exfiltration possible via query parameters on upload endpoints

Published Aug 21, 2026 · Updated Aug 26, 2026 · Assigned by GitHub_M

Description

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 products

VendorProductAffectedFixed
OctoPrint OctoPrint < 1.11.8, >= 2.0.0rc1, < 2.0.0rc3 —

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI octoprint < 1.11.8 1.11.8 GHSA-j4h9-pm27-4rfw
PyPI octoprint >= 2.0.0rc1, < 2.0.0rc3 2.0.0rc3 GHSA-j4h9-pm27-4rfw
PyPI octoprint < 1.11.8 · >= 2.0.0rc1, < 2.0.0rc3 1.11.8, 2.0.0rc3 PYSEC-2026-2687

References