CVE-2026-59922
Fixed in a distro release EPSS <1%CVSS 7.5
Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a run of closed tilde, equals-sign, or caret marker pairs around a character causes quadratic work in src/mistune/plugins/formatting.py when the strikethrough, mark, or insert plugin scans for matching markers from each possible start position, allowing denial of service through CPU exhaustion. 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 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 |