Vulnerability · Published Oct 19, 2026 · Assigned by GitHub_M
CVE-2026-111759markdown-it: Quadratic complexity in smartquotes with unmatched closing quotes
High 7.5
In plain English
A high-severity uncontrolled resource consumption in markdown-it from markdown-it. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | node-markdown-it | no fix listed | DEBIAN-CVE-2026-111759 |
| Debian:13 | node-markdown-it | no fix listed | DEBIAN-CVE-2026-111759 |
| Debian:14 | node-markdown-it | no fix listed | DEBIAN-CVE-2026-111759 |
| Ubuntu:22.04:LTS | node-markdown-it | no fix listed | UBUNTU-CVE-2026-111759 |
| Ubuntu:24.04:LTS | node-markdown-it | no fix listed | UBUNTU-CVE-2026-111759 |
| Ubuntu:26.04:LTS | node-markdown-it | no fix listed | UBUNTU-CVE-2026-111759 |
| Ubuntu:26.10 | node-markdown-it | no fix listed | UBUNTU-CVE-2026-111759 |
| npm | markdown-it | 14.3.2 | GHSA-r7fv-28h4-cvq7 |
| npm | markdown-it | 15.0.2 | GHSA-r7fv-28h4-cvq7 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| markdown-it | markdown-it | >= 15.0.0, < 15.0.2< 14.3.2 |
Weakness: CWE-400, CWE-407 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/markdown-it/markdown-it/security/advisories/GHSA-r7fv-28h4-cvq7 x_refsource_CONFIRM
- https://github.com/markdown-it/markdown-it/commit/1b379c1b6d0522421bd1a51b77337c79af2c8670 x_refsource_MISC
- https://github.com/markdown-it/markdown-it/commit/cf27366035edf9196667110c47d9d67b030a4152 x_refsource_MISC
- https://github.com/markdown-it/markdown-it/commit/daf5a3c32303e5d9de01b12eeb725fb5990b8162 x_refsource_MISC
- https://github.com/markdown-it/markdown-it/releases/tag/14.3.2 x_refsource_MISC
- https://github.com/markdown-it/markdown-it/releases/tag/15.0.2 x_refsource_MISC