CVE-2026-58487
MediumCVSS 5.1Exploitation Probability (EPSS)
Low risk28th percentile - higher than 28% of all known CVEs
Summary
HedgeDoc before version 1.11.0 was vulnerable to stored HTML Injection due to unsafe handling of the local-part of registered email addresses. An attacker could register a specially crafted email address and inject arbitrary HTML into pages viewed by other users.
Risk Assessment
The risk involves the ability to alter page content and embed attacker-controlled resources such as cross-origin iframes, potentially leading to data theft or phishing.
Recommendation
Immediately update HedgeDoc to version 1.11.0 or later, which contains the fix for this vulnerability.
Other vulnerabilities in HedgeDoc
See all- CVE-2026-58489Medium
In HedgeDoc prior to version 1.11.0, the GitHub Gist export flow had an OAuth2 state validation flaw. The state parameter was only checked for presence, not validated against the user's session, allowing an attacker to forge a callback URL. A logged-in victim clicking a crafted link could export their private note to an attacker-controlled Gist.
- CVE-2026-58486High
HedgeDoc before version 1.11.0 was vulnerable to a YAML alias bomb in note frontmatter. Unsafe parsing with js-yaml.load expanded YAML anchor aliases, creating huge object structures and excessive CPU consumption. An attack could block the Node.js event loop for about 235 seconds per request, causing denial of service (DoS).
- CVE-2026-58488Medium
HedgeDoc versions prior to 1.11.0 allowed attackers to bypass rate-limiting on /login and /register routes by spoofing the cf-connecting-ip header. The application trusted this header even when the request did not originate from Cloudflare, enabling login spam or mass account creation.
- CVE-2023-38487Medium
HedgeDoc prior to version 1.9.9 allowed the creation of notes with an alias matching the ID of existing notes, effectively hiding the original notes. Users could exploit this vulnerability to manipulate note content and prevent access to original notes.
Original NVD description (English source)
HedgeDoc is an open source, real-time, collaborative, markdown notes application. Prior to version 1.11.0, due to unsafe handling of the local-part of registered email addresses, HedgeDoc was vulnerable to stored HTML Injection through its publish and slide views. An attacker could register a specially crafted email address and inject arbitrary HTML into pages viewed by other users. HedgeDoc accepted RFC 5321 quoted-string local-parts in email addresses during registration. The local-part was then reused as the user's display name without escaping and rendered into HTML in multiple places, including publish and slide views as well as the collaborative editor. An attacker could break out of an HTML attribute and inject arbitrary markup into the page. While the deployed Content-Security-Policy prevented straightforward inline JavaScript execution, the injected HTML was still sufficient to alter page content and embed attacker-controlled resources such as cross-origin iframes. This issue was fixed in version 1.11.0.