Vulnerability Description
HedgeDoc is an open source, real-time, collaborative, markdown notes application. Prior to version 1.11.0, HedgeDoc was vulnerable to a YAML alias bomb due to unsafe processing of the note frontmatter. HedgeDoc parsed frontmatter with js-yaml.load (js-yaml v3) via @hedgedoc/meta-marked, which resolved YAML anchor aliases. A compact malicious payload could therefore expand into a huge object structure, consuming excessive CPU. This expansion ran on every request to the publish view (/s/<shortid>) and, when placed under the opengraph key, the editor view (/<noteId>). A ten-level alias bomb could block the single Node.js event loop for roughly 235 seconds per request, causing concurrent requests to hang or drop and rendering the instance unavailable (DoS). Because the note was stored in the database, the impact survived process restarts until the note was removed. toobusy-js did not reliably mitigate the worst cases, as the event loop was saturated before the middleware could respond. This issue was fixed in version 1.11.0.
Related Weaknesses (CWE)
References
- https://github.com/hedgedoc/hedgedoc/commit/c489497e451887bfe400434c5a010940051e
- https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-qj78-mjch-wwrv
FAQ
What is CVE-2026-58486?
CVE-2026-58486 is a documented vulnerability. HedgeDoc is an open source, real-time, collaborative, markdown notes application. Prior to version 1.11.0, HedgeDoc was vulnerable to a YAML alias bomb due to unsafe processing of the note frontmatter...
How severe is CVE-2026-58486?
CVSS scoring is not yet available for CVE-2026-58486. Check NVD for updates.
Is there a patch for CVE-2026-58486?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.