CVE-2026-76098
Published:August 24, 2026
Updated:September 24, 2026
Mistune is a Python Markdown parser with renderers and plugins. Versions 3.3.0 through 3.3.2 are vulnerable to DoS through deeply nested tokens. HTML rendering creates deeply nested emphasis tokens from consecutive asterisk characters, and recursive rendering in HTMLRenderer.render_token() can exceed Python's recursion limit and raise RecursionError, allowing crafted Markdown to crash a parsing process. This issue is fixed in version 3.3.3
Affected Packages
mistune (CONDA):
Affected version(s) >=3.3.1 <3.3.3Fix Suggestion:
Update to version 3.3.3https://github.com/lepture/mistune.git (GITHUB):
Affected version(s) >=v3.3.0 <v3.3.3Fix Suggestion:
Update to version v3.3.3mistune (PYTHON):
Affected version(s) >=3.3.0 <3.3.3Fix Suggestion:
Update to version 3.3.3Related Resources (7)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Uncontrolled Recursion
EPSS
Base Score:
0.28