Part-DB: SVG Sanitization Bypass via Extension Spoofing Leads to Stored XSS in Attachment Viewer

Part-DB is an open source inventory management system for electronic components. Prior to version 2.12.3, Part-DB-server sanitizes SVG files based solely on the user-controlled filename extension rather than actual file content type. An authenticated attacker can upload a malicious SVG with JavaScript payload using a non-SVG extension (e.g., .jpg), bypassing sanitization entirely. When any user views the attachment inline, the browser receives Content-Type: image/svg+xml and executes the embedded script in the Part-DB origin. This issue has been patched in version 2.12.3.