7.5highHigh

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

What the metrics mean

  • It is reachable over a network, without needing local access.
  • For an attacker who can reach it, no special conditions are needed to exploit it.
  • To exploit it, no account is needed.
  • Beyond that, no action by a user is required.

Scoring

CVSS
7.5 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness
CWE-674
Assigned by
security-advisories@github.com

Dates

Published
2026-08-24
Last modified
2026-09-09
Sources
NVD

References