CVE-2026-111759: markdown-it Uncontrolled Resource Consumption

Vulnerability summary

CVE-2026-111759 is a high (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in markdown-it. EPSS estimates a 0.60% chance of exploitation in the next 30 days, higher than 47.8% of scored vulnerabilities.

Timeline

1. 19-10-2026
   PublishedVulnerability first disclosed.
2. 19-10-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-400Uncontrolled Resource ConsumptionThe product does not properly control the allocation and maintenance of a limited resource.
• CWE-407Inefficient Algorithmic ComplexityAn algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.