copyparty: volflag `nohtml` did not block javascript in svg files
Date: 2026-03
Affected: pip/copyparty
Attack vector: xss
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2026-30974
CWE: CWE-79
CVSS: 4.6 (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N)

### Summary The `nohtml` config option, intended to prevent execution of JavaScript in user-uploaded HTML files, did not apply to SVG images. ### Details A user with write-permission could upload an SVG containing embedded JavaScript, which would execute in the context of whichever user opens it. This in itself is not a vulnerability; it is intended behavior according to [the SVG spec](https://www.w3.org/TR/SVG11/script.html). The vulnerability is that the `nohtml` volflag, when enabled, did not prevent this. `nohtml`, intended for use on volumes which contains untrusted files, would correctly prevent execution of javascript in HTML files, but did not consider SVG images. This has been fixed in v1.20.11. ### Impact The malicious JavaScript could move or delete existing files on the server, or upload new files, using the account of the person who opens the SVG.


Mitigations:

Architectural layers (MAESTRO):