CVE-2026-59926
Fixed in a distro release EPSS <1%CVSS 5.3
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.
Products: lepture mistune
Fixed upstream
| Ecosystem | Package | Fixed in |
|---|---|---|
| PyPI | mistune | 3.3.0 |
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Debian 13 | mistune | no fix |
| Debian 14 | mistune | 3.1.4-1 |
| SUSE Linux Enterprise Server 16.0 | python-mistune | 3.1.3-160000.5.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | python-mistune | 3.1.3-160000.5.1 |
| Ubuntu 16.04 LTS | mistune | no fix |
| Ubuntu 18.04 LTS | mistune | no fix |
| Ubuntu 20.04 LTS | mistune | no fix |
| Ubuntu 22.04 LTS | mistune | no fix |
| Ubuntu 24.04 LTS | mistune | no fix |
| Ubuntu 25.10 | mistune | no fix |
| Ubuntu 26.04 LTS | mistune | no fix |
| Ubuntu 26.10 | mistune | no fix |
| openSUSE Leap 16.0 | python-mistune | 3.1.3-160000.5.1 |