CVE-2026-58487 HedgeDoc: Stored HTML injection via email local-part
Attackers can inject arbitrary HTML into HedgeDoc pages via crafted email addresses, altering content and embedding malicious resources for other users.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-58487?
CVE-2026-58487 is a medium-severity cross-site scripting vulnerability in hedgedoc, published on 13 Jul 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
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.
Which versions are affected by CVE-2026-58487?
How do I fix CVE-2026-58487?
No fix has been published for CVE-2026-58487 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-58487 being exploited?
There is no known exploitation of CVE-2026-58487 in the wild and no public exploit code.
Sources
Also known as GHSA-6c2w-8w96-3pcv.