markdown-it up to 14.3.1/15.0.1 smartquotes rule resource consumption

Summaryinfo

A vulnerability marked as problematic has been reported in markdown-it up to 14.3.1/15.0.1. Affected by this issue is some unknown functionality of the component smartquotes rule. The manipulation leads to resource consumption. This vulnerability is traded as CVE-2026-111759. It is possible to initiate the attack remotely. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in markdown-it up to 14.3.1/15.0.1. This issue affects an unknown code of the component smartquotes rule. The manipulation with an unknown input leads to a resource consumption vulnerability. Using CWE to declare the problem leads to 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. Impacted is availability. The summary by CVE is:

markdown-it is a Markdown parser. Prior to 14.3.2 and 15.0.2, when typographer: true is enabled, specially crafted Markdown can cause quadratic processing time in the smartquotes rule, potentially leading to denial of service in applications processing untrusted input. Many opening double quotes followed by unmatched closing single quotes cause repeated scans of the entire opener stack. The same issue occurs with the quote types reversed. The default configuration (typographer: false) is not affected, but this option is enabled with high probability. This issue is fixed in versions 14.3.2 and 15.0.2.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-111759 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. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

Upgrading to version 14.3.2 or 15.0.2 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• markdown-it

Version

• 14.3.0
• 14.3.1
• 15.0.0
• 15.0.1

Website

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

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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