CVE-2020-26286

Name: CVE-2020-26286
Creator: NVD / NIST
Published: 2020-12-29T00:15:12.593+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.42%

Last modified Jun 17, 2026

CVE-2020-26286 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 1.42% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Probability

1.42%

69.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-434

Affected Software

Vendor	Product	Versions
Hedgedoc	Hedgedoc	< 1.7.1

References

https://github.com/hedgedoc/hedgedoc/commit/e9306991cdb5ff2752c1eeba3fedba42aec3c2d8Patch, Third Party Advisory
https://github.com/hedgedoc/hedgedoc/releases/tag/1.7.1Third Party Advisory
https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-wcr3-xhv7-8gxcThird Party Advisory
https://github.com/hedgedoc/hedgedoc/commit/e9306991cdb5ff2752c1eeba3fedba42aec3c2d8Patch, Third Party Advisory
https://github.com/hedgedoc/hedgedoc/releases/tag/1.7.1Third Party Advisory
https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-wcr3-xhv7-8gxcThird Party Advisory

Timeline

Published: Dec 29, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-26286?

How severe is CVE-2020-26286?

CVE-2020-26286 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.42% probability of exploitation in the next 30 days.

How do I fix CVE-2020-26286?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-26286?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST