CVE-2026-48988
MEDIUM
5.3
CVSS 3.1
Description
markdown-it is a Markdown parser. Versions 14.1.1 and below contain a denial-of-service vulnerability when typographer: true is enabled, due to quadratic (O(n^2)) processing in the smartquotes rule. The issue stems from repeatedly modifying strings with replaceAt(), which performs O(n) slicing and concatenation per quote character. This can cause excessive CPU consumption when parsing quote-heavy, user-supplied markdown and may let attackers degrade or disrupt service availability. Although typographer is disabled by default, many production apps enable it for smart typography, making the issue relevant. This issue has been fixed in version 14.2.0.
Metadata
Severity & Metrics
5.3
MEDIUM CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Affected products (1)
| Vendor | Product | Platform | Versions |
|---|---|---|---|
| markdown-it | markdown-it | — | < 14.2.0 |
Weakness (CWE)
| CWE | Source | Description |
|---|---|---|
| CWE-400 | cna | CWE-400: Uncontrolled Resource Consumption |
CVSS scores (1)
| Score | Severity | Version | Source | Vector |
|---|---|---|---|---|
| 5.3 | MEDIUM | 3.1 | cna | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
References (2)
- https://github.com/markdown-it/markdown-it/security/advisories/GHSA-6v5v-wf23-fmfq https://github.com/markdown-it/markdown-it/security/advisories/GHSA-6v5v-wf23-fmfq
- https://github.com/markdown-it/markdown-it/commit/9ce2087562c45d1e5ddd9f76b990f4b3fbe040e5 https://github.com/markdown-it/markdown-it/commit/9ce2087562c45d1e5ddd9f76b990f4b3fbe040e5