Markdown-It Project: >> Markdown-It >> 2.1.1 Security Vulnerabilities
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.
CVSS Score
5.3
EPSS Score
0.004
Published
2026-06-17
A vulnerability was found in markdown-it up to 2.x. It has been classified as problematic. Affected is an unknown function of the file lib/common/html_re.js. The manipulation leads to inefficient regular expression complexity. Upgrading to version 3.0.0 is able to address this issue. The name of the patch is 89c8620157d6e38f9872811620d25138fc9d1b0d. It is recommended to upgrade the affected component. The identifier of this vulnerability is VDB-216852.
CVSS Score
3.5
EPSS Score
0.009
Published
2022-12-27
markdown-it is a Markdown parser. Prior to version 1.3.2, special patterns with length greater than 50 thousand characterss could slow down the parser significantly. Users should upgrade to version 12.3.2 to receive a patch. There are no known workarounds aside from upgrading.
CVSS Score
5.3
EPSS Score
0.022
Published
2022-01-10