Copyparty is a portable file server. Prior to v1.20.11., the nohtml config option, intended to prevent execution of JavaScript in user-uploaded HTML files, did not apply to SVG images. A user with write-permission could upload an SVG containing embedded JavaScript, which would execute in the context of whichever user opens it. This has been fixed in v1.20.11.
https://github.com/9001/copyparty/security/advisories/GHSA-m6hv-x64c-27mm
https://github.com/9001/copyparty/releases/tag/v1.20.11
https://github.com/9001/copyparty/commit/1c9f894e149b6be3cc7de81efc93a4ce4766e0e5