medium6.1
CVE-2026-44896
Mistune has XSS via unescaped figclass/figwidth in Figure directive
Impact
Mistune is a Python Markdown parser with renderers and plugins. In 3.2.0 and earlier, in src/mistune/directives/image.py, the render_figure() function concatenates figclass and figwidth options directly into HTML attributes without escaping. This allows attribute injection and XSS even when HTMLRenderer(escape=True) is used, because these values bypass the inline renderer. Version 3.2.1 contains a patch.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | mistune | <= 3.2.0 | 3.2.1 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Mistune Project | Mistune | through 3.2.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-58cw-g322-p94v
- https://github.com/lepture/mistune/security/advisories/GHSA-58cw-g322-p94v
- https://nvd.nist.gov/vuln/detail/CVE-2026-44896
- https://github.com/lepture/mistune/commit/a3cb6e5655308797e8be021d6c7b5bab13cbace2
- https://github.com/pypa/advisory-database/tree/main/vulns/mistune/PYSEC-2026-168.yaml