CVE-2026-48988 – markdown-it: Quadratic complexity DoS in smartquotes rule via replaceAt string operations

CVE ID :CVE-2026-48988

Published : June 17, 2026, 8:54 p.m. | 48 minutes ago

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.

Severity: 0.0 | NA

Visit the link for more details, such as CVSS details, affected products, timeline, and more…