CVE-2026-76098
Mistune has Denial of Service — RecursionError via Excessive Emphasis Markers in Markdown
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th
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
| CWE | CWE-674 |
| Vendor | lepture |
| Product | mistune |
| Published | Aug 24, 2026 |
| Last Updated | Aug 24, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
lepture / mistune
>= 3.3.0, < 3.3.3