Inefficient Regular Expression Complexity Affecting mistune package, versions <2.0.3-1


Severity

Recommended
0.0
high
0
10

Snyk's Security Team recommends NVD's CVSS assessment. Learn more

Threat Intelligence

EPSS
1.62% (76th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-ECHOLATEST-MISTUNE-18306988
  • published25 Jul 2026
  • disclosed25 Jul 2022

Introduced: 25 Jul 2022

CVE-2022-34749  (opens in a new tab)
CWE-1333  (opens in a new tab)

How to fix?

Upgrade Echo:latest mistune to version 2.0.3-1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream mistune package and not the mistune package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

In mistune through 2.0.2, support of inline markup is implemented by using regular expressions that can involve a high amount of backtracking on certain edge cases. This behavior is commonly named catastrophic backtracking.

CVSS Base Scores

version 3.1