Inefficient Algorithmic Complexity Affecting mistune package, versions [,3.3.0)
Threat Intelligence
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-17895069
- published8 Jul 2026
- disclosed8 Jul 2026
- creditUnknown
Introduced: 8 Jul 2026
CVE-2026-59922 (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 through the parsing process in formatting.py when handling long sequences of ~~, ==, or ^^ markers. An attacker can cause excessive CPU consumption by submitting specially crafted input containing long runs of these markers.