What’s Vulnerable › Vulnerabilities

CVE-2026-111759: markdown-it: Quadratic complexity in smartquotes with unmatched closing quotes

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-19 · updated 2026-10-19
• Weakness: CWE-400

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.

Affected products

• markdown-it: from 15.0.0, < 15.0.2; before 14.3.2

References

• https://github.com/markdown-it/markdown-it/commit/1b379c1b6d0522421bd1a51b77337c79af2c8670
• https://github.com/markdown-it/markdown-it/commit/cf27366035edf9196667110c47d9d67b030a4152
• https://github.com/markdown-it/markdown-it/commit/daf5a3c32303e5d9de01b12eeb725fb5990b8162
• https://github.com/markdown-it/markdown-it/releases/tag/14.3.2
• https://github.com/markdown-it/markdown-it/releases/tag/15.0.2
• https://github.com/markdown-it/markdown-it/security/advisories/GHSA-r7fv-28h4-cvq7
• https://github.com/markdown-it/markdown-it/security/advisories/GHSA-r7fv-28h4-cvq7

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