Description
Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, HTMLRenderer.safe_url() does not block percent-encoded javascript URIs, allowing attacker-supplied Markdown links or images to bypass URL protections and execute script in rendered HTML. This issue is fixed in version 3.3.0.
Severity (CVSS)
| Base score | 6.1 |
|---|---|
| Severity | Medium |
| Version | CVSS 3.1 |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| Provided by | CNA |
Weaknesses
- CWE-79 — CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected products
| Vendor | Product | Versions |
|---|---|---|
| lepture | mistune | < 3.3.0 |
References
- https://github.com/lepture/mistune/security/advisories/GHSA-8c25-4j27-2rv3 (x_refsource_CONFIRM)
- https://github.com/lepture/mistune/commit/c7101fcbb6e8790e8e39157c5ca2238fc6dd6cbc (x_refsource_MISC)
- https://github.com/lepture/mistune/releases/tag/v3.3.0 (x_refsource_MISC)
Generated from the official CVE List on 09 Jul 2026 07:08 UTC.