Resource exhaustion in Markdown-It
CVE-2026-111759
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 class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Markdown-It — versions < 14.3.2, >= 15.0.0, < 15.0.2
Weakness classification (CWE)
References
- github.com/markdown-it/markdown-it/security/advisories/GHSA-r7fv-28h4-cvq7
- github.com/markdown-it/markdown-it/commit/1b379c1b6d0522421bd1a51b77337c79af2c8…
- github.com/markdown-it/markdown-it/commit/cf27366035edf9196667110c47d9d67b030a4…
- github.com/markdown-it/markdown-it/commit/daf5a3c32303e5d9de01b12eeb725fb5990b8…
- github.com/markdown-it/markdown-it/releases/tag/14.3.2
- github.com/markdown-it/markdown-it/releases/tag/15.0.2
Frequently asked questions
- What is CVE-2026-111759?
- CVE-2026-111759 is a high-severity vulnerability in Markdown-It, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-10-19.
- How severe is CVE-2026-111759?
- High severity. CVSS v3 base score is 7.5 out of 10.