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[ CVE-2026-111759 · Published 19 Oct 2026 ]

markdown-it: Quadratic complexity in smartquotes with unmatched closing quotes

CVSS 7.5 EPSS <1%Fix available

[ Why it matters ]Priority signals

  • Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official 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.

[ Fixes ]Fixes and patches

  • markdown-it 15.0.2Fixed version · GitHub Advisories · npm package markdown-it: upgrade to 15.0.2 or later (affected >= 15.0.0, < 15.0.2)
  • markdown-it 14.3.2Fixed version · GitHub Advisories · npm package markdown-it: upgrade to 14.3.2 or later (affected < 14.3.2)

[ Packages ]Affected open-source packages

[ References ]References