High severity · published Oct 19, 2026
CVE-2026-111759
markdown-it: Quadratic complexity in smartquotes with unmatched closing quotes
7.5
CVSS
0.6%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 48% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MA
markdown-it · markdown-it
>= 15.0.0, < 15.0.2; < 14.3.2 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-111759
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-111759
github.com
https://github.com/markdown-it/markdown-it/commit/1b379c1b6d0522421bd1a51b77337c79af2c8670
github.com
https://github.com/markdown-it/markdown-it/commit/cf27366035edf9196667110c47d9d67b030a4152
github.com
https://github.com/markdown-it/markdown-it/commit/daf5a3c32303e5d9de01b12eeb725fb5990b8162
github.com
https://github.com/markdown-it/markdown-it/releases/tag/14.3.2
github.com
https://github.com/markdown-it/markdown-it/releases/tag/15.0.2
github.com
https://github.com/markdown-it/markdown-it/security/advisories/GHSA-r7fv-28h4-cvq7
More from markdown-it
7.5
CVE-2026-111758
markdown-it: Quadratic-time rendering of a single multi-line link reference definition with default options (regression since 14.0)
6.1
CVE-2025-7969
Markdown-it 14.1.0 - Cross-site scripting (XSS)
5.3
CVE-2026-48988
markdown-it: Quadratic complexity DoS in smartquotes rule via replaceAt string operations
3.7
CVE-2026-111766
markdown-it: Quadratic-time denial of service in inline HTML parsing with html enabled