🛡️ CVE-2026-59926 on Ubuntu — mistune

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, render_admonition() in src/mistune/directives/admonition.py concatenates the Admonition directive :class: option into the HTML class attribute without escaping, allowing attribute injection and cross-site scripting even when HTMLRenderer escape mode is enabled. This issue is fixed in version 3.2.1.

Distribution advisory

This page covers CVE-2026-59926 as tracked by Ubuntu, for the package mistune. No fixed version has been recorded for this distribution yet.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality low, integrity low, availability none.

Affected software

UBUNTU-CVE-2026-59926 is recorded against 1 package.

  • mistune

Timeline and source

Published on 8 July 2026 and last revised on 15 July 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

ubuntu.com (Report)
www.cve.org (Report)
github.com (Report)

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2026-07-08
Updated 2026-08-11
Modified 2026-07-15
Fix URL N/A

Affected Packages

Software From version Fixed in
mistune — —

Similar Threats

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