Inefficient Algorithmic Complexity Affecting mistune package, versions [,3.3.0)
Threat Intelligence
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The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PYTHON-MISTUNE-17895066
- published8 Jul 2026
- disclosed8 Jul 2026
- creditoffset
Introduced: 8 Jul 2026
CVE-2026-59928 (opens in a new tab)How to fix?
Upgrade mistune to version 3.3.0 or higher.
Overview
Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity via the block_parser process. An attacker can cause excessive CPU consumption by submitting specially crafted Markdown documents containing numerous repeated or distinct reference-link definitions.