CVE-2026-59925: inline_parser: quadratic-time parsing on long runs of `**x**` and `***x***` emphasis pairs
lepture · mistune
Affected: lepture mistune · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 51% of scored CVEs
DescriptionCVE.org
Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, long sequences of well-formed double-asterisk or triple-asterisk emphasis pairs around a character cause quadratic work in src/mistune/inline_parser.py because the parser scans forward for matching close markers from every potential opening run, allowing denial of service in default Mistune parsing. This issue is fixed in version 3.3.0.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- lepture · mistune< 3.3.0
On the Atlas
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CoverageNo articles yet
No CyberSIXT article names CVE-2026-59925 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.