Executive brief
InvenTree is an open-source inventory management system that generates reports and labels as PDF documents. Privileged users who can author report or label templates can trick the PDF rendering engine into fetching attacker-controlled resources, potentially exposing internal files, network credentials, and other sensitive data stored on the server. This vulnerability allows attackers with staff privileges to read arbitrary files and access internal services without leaving the application.
Technical details
The vulnerability exists in InvenTree's PDF report generation via WeasyPrint, which did not restrict the URL schemes available to the HTML-to-PDF rendering function. Attackers with staff privileges and report/label template authoring permissions can embed file://, http://, or https:// URIs in templates; the unrestricted url_fetcher retrieves these resources and embeds them in PDFs, and the attach_to_model=True feature stores unprocessed PDFs as attachments, allowing recovery of fetched content. SSRF validation, file:// blocking, and URL fetching restrictions were added in version 1.4.0.
Affected products
- InvenTree InvenTree before 1.4.0
Timeline
- 2026-09-21: disclosed
- 2026-06-14: patched: Fix merged in version 1.4.0