Stirling-PDF is a locally hosted web application that performs various operations on PDF files. Prior to version 1.1.0, when using the /api/v1/convert/html/pdf endpoint to convert HTML to PDF, the backend calls a third-party tool to process it and includes a sanitizer for security sanitization which can be bypassed and result in SSRF. This issue has been patched in version 1.1.0.
https://github.com/Stirling-Tools/Stirling-PDF/security/advisories/GHSA-xw8v-9mfm-g2pm
https://github.com/Stirling-Tools/Stirling-PDF/commit/7d6b70871bad2a3ff810825f7382c49f55293943