Bug 2498156 (CVE-2026-59928) - CVE-2026-59928 mistune: Mistune: Denial of Service via crafted Markdown document with reference-link definitions
Summary: CVE-2026-59928 mistune: Mistune: Denial of Service via crafted Markdown docum...
Keywords:
Status: NEW
Alias: CVE-2026-59928
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:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-07-08 17:02 UTC by OSIDB Bzimport
Modified: 2026-07-09 11:52 UTC (History)
17 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-07-08 17:02:31 UTC 
Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a Markdown document containing many repeated or distinct reference-link definitions causes quadratic work in src/mistune/block_parser.py and the ref_links environment dictionary handling, allowing denial of service through CPU exhaustion. This issue is fixed in version 3.3.0.
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