Bug 2498142 (CVE-2026-59923) - CVE-2026-59923 mistune: Mistune: Arbitrary code execution through crafted Markdown links
Summary: CVE-2026-59923 mistune: Mistune: Arbitrary code execution through crafted Mar...
Keywords:
Status: NEW
Alias: CVE-2026-59923
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 2498461 2498464 2498469
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-07-08 17:01 UTC by OSIDB Bzimport
Modified: 2026-07-10 11:22 UTC (History)
13 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-07-08 17:01:42 UTC 
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.
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