Cross-site scripting in HedgeDoc - CVE-2026-25642
Published: April 25, 2026
Vulnerability identifier: #VU127927
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Green
CVE-ID: CVE-2026-25642
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 attacker to host malicious interactive web content that can facilitate phishing.
The vulnerability exists due to cross-site scripting in the /uploads/ endpoint when serving uploaded SVG files without the intended security headers. A remote attacker can upload a specially crafted SVG file and directly link to it to host malicious interactive web content that can facilitate phishing.
This impacts instances using the filesystem backend for media uploads, and user interaction is required for a victim to open the link.
How to mitigate CVE-2026-25642
Install security update from vendor's website.