Cross-site scripting in HedgeDoc - #VU127926
Published: April 25, 2026
Vulnerability identifier: #VU127926
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear
CVE-ID: N/A
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: HedgeDoc
Affected software:
HedgeDoc
HedgeDoc
Detailed vulnerability description
The vulnerability allows a remote user to execute JavaScript in the context of the instance's domain.
The vulnerability exists due to improper neutralization of input during web page generation in SVG upload handling when including an uploaded SVG file into a note using iframe tags. A remote user can upload a specially crafted SVG file and include it in a note to execute JavaScript in the context of the instance's domain.
This impacts instances with SVG uploading enabled, especially when using the local filesystem backend.
Remediation
Install security update from vendor's website.