CVE-2026-76098CWE-674

CVE-2026-76098

High · published August 25, 2026

CVSS v3.1
7.5
EPSS
0%
Percentile
41.1
In the wild
Unconfirmed
What it is

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

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00488 · 41.1th percentile
Weakness
CWE-674 · Uncontrolled Recursion
Published
2026-08-25T00:17Z
References (3)
https://github.com/lepture/mistune/commit/0938fb7 · [email protected]https://github.com/lepture/mistune/security/advisories/GHSA-6m44-fpc8-c3rq · [email protected]https://github.com/lepture/mistune/security/advisories/GHSA-6m44-fpc8-c3rq · 134c704f-9b21-4f2e-91b3-4a467353bcc0
EPSS history
Timeline
  • 26 AUG 08:27Z
    EPSS moved — → 0%
    epss
  • 24 AUG 20:05Z
    Mistune has Denial of Service — RecursionError via Excessive Emphasis Markers in Markdown
    cvelistv5