XSS in Lepture Mistune

CVE-2026-44896

Mistune is a Python Markdown parser with renderers and plugins. In 3.2.0 and realier, in src/mistune/directives/image.py, the render_figure() function concatenates figclass and figwidth options directly into HTML attributes without escapin…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.000 (9.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-44896?
CVE-2026-44896 is a medium-severity vulnerability in Lepture Mistune, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-05-26.
How severe is CVE-2026-44896?
Medium severity. CVSS v3 base score is 6.1 out of 10.