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

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Mon, 24 Aug 2026 20:15:00 +0000

Type Values Removed Values Added
Description 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
Title Mistune has Denial of Service — RecursionError via Excessive Emphasis Markers in Markdown
Weaknesses CWE-674
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-24T20:17:07.057Z

Reserved: 2026-08-18T21:17:32.201Z

Link: CVE-2026-76098

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-24T20:17:19.330

Modified: 2026-08-24T20:17:19.330

Link: CVE-2026-76098

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses