HedgeDoc up to 1.10.x YAML Parser load frontmatter resource consumption

Summaryinfo

A vulnerability was found in HedgeDoc up to 1.10.x. It has been declared as problematic. Affected by this vulnerability is the function Load of the component YAML Parser. Executing a manipulation of the argument frontmatter can lead to resource consumption. This vulnerability is tracked as CVE-2026-58486. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability has been found in HedgeDoc up to 1.10.x and classified as problematic. This vulnerability affects the function load of the component YAML Parser. The manipulation of the argument frontmatter with an unknown input leads to a resource consumption vulnerability. The CWE definition for the vulnerability is CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. As an impact it is known to affect availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability was named CVE-2026-58486 since 06/30/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

Upgrading to version 1.11.0 eliminates this vulnerability.

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Productinfo

Name

• HedgeDoc

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10

Website

• Product: https://github.com/hedgedoc/hedgedoc/

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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