---
id: CVE-2026-30974
aliases:
  - GHSA-m6hv-x64c-27mm
  - PYSEC-2026-2137
title: 'copyparty: volflag `nohtml` did not block javascript in svg files'
summary: 'copyparty: volflag `nohtml` did not block javascript in svg files'
severity: medium
cvss: 4.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N'
vendor: copyparty
product: copyparty
ecosystem: pip
affected:
  - copyparty < 1.20.11
patched:
  - copyparty 1.20.11
published: '2026-03-10'
updated: '2026-07-13'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-m6hv-x64c-27mm'
references:
  - url: 'https://github.com/9001/copyparty/security/advisories/GHSA-m6hv-x64c-27mm'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-30974'
  - url: >-
      https://github.com/9001/copyparty/commit/1c9f894e149b6be3cc7de81efc93a4ce4766e0e5
  - url: 'https://github.com/9001/copyparty'
  - url: 'https://github.com/9001/copyparty/releases/tag/v1.20.11'
tags:
  - osv
  - pip
epss: 0.00343
epssPercentile: 0.2503
ingestedAt: '2026-07-13T18:58:00.382Z'
---

## Overview

### 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.

## Affected packages

- `copyparty < 1.20.11`

## Remediation

Upgrade to a patched release:

- `copyparty 1.20.11`