CVE-2020-26286 json
Arbitary file upload
published 2020-12-28 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-18854
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.4%
- EPSS 1.4% chance of exploitation in 30 days, percentile 73%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- hedgedoc hedgedoc 1.7.1
Exploit prediction
1.44% chance of exploitation in the next 30 days, higher than 73% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:P/A:N |
Affected products
- hedgedoc hedgedoc
Classification
- Weakness
-
- CWE-434 Unrestricted Upload of File with Dangerous Type
References
-
github.com
/hedgedoc/hedgedoc/commit/e9306991cdb5ff2752c1eeba3fedba42aec3c2d8
patch, third-party-advisory
-
github.com
/hedgedoc/hedgedoc/security/advisories/GHSA-wcr3-xhv7-8gxc
third-party-advisory
-
github.com
/hedgedoc/hedgedoc/releases/tag/1.7.1
third-party-advisory
Sources
- CVE List CVE-2020-26286
- NVD CVE-2020-26286
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