AIKIDO-2026-972512

TL;DR

Curator's upload components fall back to a default accepted-file-types list that includes text/html, application/xhtml+xml, text/javascript, application/xml and application/octet-stream when no explicit accepted types are configured. An authenticated user permitted to upload media can upload an HTML file that is stored unmodified and later served from the application's own origin as text/html. When another user opens the file the embedded script executes in their session, allowing stored cross-site scripting and theft of a more privileged session. The fix removes executable content types from the default list and serves restricted types with a nosniff header and attachment disposition.