Insufficient Verification of Data Authenticity 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-17895072
- published8 Jul 2026
- disclosed8 Jul 2026
- creditoffset
Introduced: 8 Jul 2026
CVE-2026-59930 (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 Insufficient Verification of Data Authenticity via the toc process. An attacker can interfere with same-page navigation, CSS selectors, or JavaScript handlers by creating content with predictable id attributes that collide with automatically generated heading anchors.