CVE-2026-59929
Fixed in a distro release EPSS <1%CVSS 6.1
Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the safe_url filter in src/mistune/renderers/html.py blocks only javascript:, vbscript:, file:, and data: schemes, allowing legacy or chained schemes such as feed:, view-source:, jar:, livescript:, mocha:, ms-its:, mk:, and res: to reach rendered href and src attributes and potentially execute script in affected user agents. This issue is fixed in version 3.3.0.
Products: lepture mistune
Fixed upstream
| Ecosystem | Package | Fixed in |
|---|---|---|
| PyPI | mistune | 3.3.0 |
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Debian 12 | mistune | no fix |
| Debian 13 | mistune | no fix |
| Debian 14 | mistune | no fix |
| 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 |