markdown-it up to 14.3.2/15.0.2 Link Reference Definition reference.ts allocation of resources

Summaryinfo

A vulnerability, which was classified as problematic, has been found in markdown-it up to 14.3.2/15.0.2. This issue affects some unknown processing of the file src/rules_block/reference.ts of the component Link Reference Definition. The manipulation leads to allocation of resources. This vulnerability is listed as CVE-2026-111758. The attack may be initiated remotely. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in markdown-it up to 14.3.2/15.0.2. It has been rated as problematic. This issue affects an unknown functionality of the file src/rules_block/reference.ts of the component Link Reference Definition. The manipulation with an unknown input leads to a allocation of resources vulnerability. Using CWE to declare the problem leads to CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. Impacted is availability. The summary by CVE is:

markdown-it is a Markdown parser. From versions 14.1.0 to before 14.3.3, and 15.0.0 to before 15.0.3, a link reference definition whose label or title is never closed is O(n²) with default options. Continuation lines are pulled lazily with str += lineContent in src/rules_block/reference.ts, and the subsequent charCodeAt and slice calls flatten the V8 cons-string, copying everything collected so far; this runs before the rule decides the definition is invalid. No options are required to trigger it. This issue has been patched in versions 14.3.3 and 15.0.3.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-111758 since 10/16/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

Upgrading to version 14.3.3 or 15.0.3 eliminates this vulnerability.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Name

• markdown-it

Version

• 14.3.0
• 14.3.1
• 14.3.2
• 15.0.0
• 15.0.1
• 15.0.2

Website

• Product: https://github.com/markdown-it/markdown-it/

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