Inefficient Algorithmic Complexity Affecting mistune package, versions [3.2.0,3.3.0)
Threat Intelligence
Exploit Maturity
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
Proof of Concept
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Test your applications- Snyk IDSNYK-PYTHON-MISTUNE-21460683
- published23 Oct 2026
- disclosed22 Oct 2026
- creditUnknown
Introduced: 22 Oct 2026
NewCVE-2026-115347 (opens in a new tab)Common Vulnerabilities and Exposures (CVE) are common identifiers for publicly known security vulnerabilities
Common Weakness Enumeration (CWE) is a category system for software weaknesses
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 unbounded nesting depth in the inline parser, where processing deeply nested inline elements (such as emphasis or links) causes uncontrolled resource consumption. An attacker can submit input with excessive inline nesting to exhaust CPU or memory resources and crash the process.