CVE-2025-32391: HedgeDoc is an open source, real-time, collaborative, markdown notes application. Prior to 1.10.3, a malicious SVG file uploaded to HedgeDoc results i...

Description

HedgeDoc is an open source, real-time, collaborative, markdown notes application. Prior to 1.10.3, a malicious SVG file uploaded to HedgeDoc results in the possibility of XSS when opened in a new tab instead of the editor itself. The XSS is possible by exploiting the JSONP capabilities of GitHub Gist embeddings. Only instances with the local filesystem upload backend or special configurations, where the uploads are served from the same domain as HedgeDoc, are vulnerable. This vulnerability is fixed in 1.10.3. When upgrading to HedgeDoc 1.10.3 is not possible, instance owners could add the following headers for all routes under /uploads as a first-countermeasure: Content-Disposition: attachment and Content-Security-Policy: default-src 'none'. Additionally, the external URLs in the script-src attribute of the Content-Security-Policy header should be removed.

Metrics

CVSS 3.1

4.6/10

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

EPSS Probability

0.26%

17.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Hedgedoc	Hedgedoc	< 1.10.3

References

Timeline

Published: Apr 10, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-32391?

HedgeDoc is an open source, real-time, collaborative, markdown notes application. Prior to 1.10.3, a malicious SVG file uploaded to HedgeDoc results in the possibility of XSS when opened in a new tab instead of the editor itself. The XSS is possible by exploiting the JSONP capabilities of GitHub Gist embeddings. Only instances with the local filesystem upload backend or special configurations, where the uploads are served from the same domain as HedgeDoc, are vulnerable. This vulnerability is fixed in 1.10.3. When upgrading to HedgeDoc 1.10.3 is not possible, instance owners could add the following headers for all routes under /uploads as a first-countermeasure: Content-Disposition: attachment and Content-Security-Policy: default-src 'none'. Additionally, the external URLs in the script-src attribute of the Content-Security-Policy header should be removed.

How severe is CVE-2025-32391?

CVE-2025-32391 has a CVSS score of 4.6/10 (MEDIUM severity). The EPSS model estimates a 0.26% probability of exploitation in the next 30 days.

How do I fix CVE-2025-32391?

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.