CVE-2026-44708CWE-79

Mistune Math Plugin XSS Escape Bypass

Medium · published May 26, 2026

CVSS v3.1
6.1
EPSS
0%
Percentile
18.5
In the wild
Unconfirmed
What it is

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, the mistune math plugin renders inline math ($...$) and block math ($$...$$) by concatenating the raw user-supplied content directly into the HTML output without any HTML escaping. This occurs even when the parser is explicitly created with escape=True, which is supposed to guarantee that all user-controlled text is sanitised before reaching the DOM. This vulnerability is fixed in 3.2.1.

The record
Technical detail
CVSS v3.1
6.1 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00271 · 18.5th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-05-26T20:39Z
EPSS history
Timeline
  • 26 MAY 20:39Z
    Mistune Math Plugin XSS Escape Bypass
    cvelistv5