CVE-2026-58486 Details
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.
A denial-of-service vulnerability has been identified in HedgeDoc versions prior to 1.11.0. The issue arises from the unsafe processing of YAML frontmatter in notes, which allows for the creation of a 'YAML alias bomb'. This type of payload, when expanded, consumes excessive CPU resources, blocking the Node.js event loop and causing the application to become unresponsive. The vulnerability is particularly concerning because the malicious note is stored in the database, allowing the impact to persist across application restarts.
Users can upgrade to HedgeDoc version 1.11.0 or later, where this vulnerability has been fixed. If an upgrade is not possible, note creation can be restricted and any existing malicious notes can be removed directly from the database.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jul 13, 2026CISA-ADP
Assessed Jul 14, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/hedgedoc/hedgedoc/commit/c489497e451887bfe400434c5a010940051e9890 | [email protected] | Source CodeVendor |
| https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-qj78-mjch-wwrv | [email protected] | AdvisoryRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-400 | Uncontrolled Resource Consumption | [email protected] |
| CWE-409 | Improper Handling of Highly Compressed Data (Data Amplification) | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| HedgeDoc | <= 1.10.8 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 14, 2026 | CVE Modified | CISA-ADP |
| Jul 13, 2026 | New CVE Received | [email protected] |