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.

Classification

CVE ID: CVE-2025-32391

CVSS Base Severity: MEDIUM

CVSS Base Score: 6.4

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

Affected Products

Vendor: hedgedoc

Product: hedgedoc

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.03% (probability of being exploited)

EPSS Percentile: 7.91% (scored less or equal to compared to others)

EPSS Date: 2025-04-20 (when was this score calculated)

Stakeholder-Specific Vulnerability Categorization (SSVC)

SSVC Exploitation: none

SSVC Technical Impact: partial

SSVC Automatable: false

References

https://nvd.nist.gov/vuln/detail/CVE-2025-32391
https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-3983-rrqh-mvx5
https://github.com/hedgedoc/hedgedoc/commit/0636b5c20b7097afccfa6641830352ad068ef964
https://github.com/hedgedoc/hedgedoc/commit/3f520ea59abf912c66d7443cb99f29a567c47748
https://github.com/hedgedoc/hedgedoc/commit/d2585fbd3b398b3359f6f88aa1fda8f4ecf2f78d

Timeline