Vulnerability in Lepture Mistune
CVE-2026-76098
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
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Lepture Mistune — versions >= 3.3.0, < 3.3.3
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_CONFIRM)
Frequently asked questions
- What is CVE-2026-76098?
- CVE-2026-76098 is a high-severity vulnerability in Lepture Mistune, classified under Uncontrolled Recursion. CVSS score: 7.5/10. Published 2026-08-24.
- How severe is CVE-2026-76098?
- High severity. CVSS v3 base score is 7.5 out of 10.