CVE-2026-111759
HighCVSS 7.5Summary
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, leading to denial of service. The issue occurs with many opening double quotes followed by unmatched closing single quotes.
Risk Assessment
Applications processing untrusted input may experience resource exhaustion and denial of service. The default configuration (typographer: false) is not affected, but the option is often enabled.
Recommendation
Update markdown-it to version 14.3.2 or 15.0.2 (or later). Consider disabling typographer for untrusted input.
Other vulnerabilities in markdown-it
See all- CVE-2026-111766Low
markdown-it is a Markdown parser. Prior to 14.3.3 and 15.0.3, when the html option or commonmark preset is enabled and constructs occur inside a paragraph, attacker-controlled Markdown containing repeated unterminated inline HTML comments, processing instructions, declarations, or CDATA sections reaches src/rules_inline/html_inline.ts. Its HTML_TAG_RE match searches the remaining suffix for the appropriate terminator; when no terminator is present, parsing advances to the next opener and repeats the match over overlapping input, causing quadratic processing and denial of service through event-loop blocking or an unresponsive browser main thread. HTML blocks and the default HTML-disabled configuration are not affected by these payloads. This issue is fixed in versions 14.3.3 and 15.0.3.
- CVE-2026-48988Medium
markdown-it is a Markdown parser that contains a denial-of-service vulnerability in versions 14.1.1 and below when typographer: true is enabled. The issue arises from quadratic processing in the smartquotes rule, leading to excessive CPU consumption when parsing quote-heavy markdown.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS