CVE-2021-39175

Name: CVE-2021-39175
Creator: NVD / NIST
Published: 2021-08-30T21:15:09.523+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.60%

Last modified Jun 17, 2026

CVE-2021-39175 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. HedgeDoc is a platform to write and share markdown. In versions prior to 1.9.0, an unauthenticated attacker can inject arbitrary JavaScript into the speaker-notes of the slide-mode feature by embedding an iframe hosting the malicious code into the slides or by embedding the HedgeDoc instance into another page. EPSS estimates a 0.60% chance of exploitation in the next 30 days.

Description

HedgeDoc is a platform to write and share markdown. In versions prior to 1.9.0, an unauthenticated attacker can inject arbitrary JavaScript into the speaker-notes of the slide-mode feature by embedding an iframe hosting the malicious code into the slides or by embedding the HedgeDoc instance into another page. The problem is patched in version 1.9.0. There are no known workarounds aside from upgrading.

Metrics

CVSS 3.1

6.1/10

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

EPSS Probability

0.60%

44.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Hedgedoc	Hedgedoc	< 1.9.0

References

https://github.com/hedgedoc/hedgedoc/pull/1369Patch, Third Party Advisory
https://github.com/hedgedoc/hedgedoc/pull/1375Patch, Third Party Advisory
https://github.com/hedgedoc/hedgedoc/pull/1513Patch, Third Party Advisory
https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-j748-779h-9697Patch, Third Party Advisory
https://github.com/hedgedoc/hedgedoc/pull/1369Patch, Third Party Advisory
https://github.com/hedgedoc/hedgedoc/pull/1375Patch, Third Party Advisory
https://github.com/hedgedoc/hedgedoc/pull/1513Patch, Third Party Advisory
https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-j748-779h-9697Patch, Third Party Advisory

Timeline

Published: Aug 30, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-39175?

How severe is CVE-2021-39175?

CVE-2021-39175 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.60% probability of exploitation in the next 30 days.

How do I fix CVE-2021-39175?

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-2021-39175?

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

Scan your code now

Source: NVD / NIST