CVE-2026-121437
7.5 HIGHpublic exploit availablePublished 2026-11-03 · Updated 2026-11-03
AI analysis for this CVE has not been generated yet. Raw NVD data is shown below.
NVD description
Mistune from 3.3.0 before 3.3.4 contains a denial of service vulnerability that allows remote attackers to exhaust CPU through quadratic-time emphasis delimiter processing. Attackers can submit small markdown documents with repeated patterns like "*a_b" to trigger an O(n²) index-fixup loop, stalling workers for seconds.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weaknesses
CWE-407
Public exploit & PoC references
All references
- https://github.com/lepture/mistune/commit/b4dd3284e52ec741ed9a227db29ade9017828e90
- https://github.com/lepture/mistune/security/advisories/GHSA-qp42-r9j6-83g9
- https://www.vulncheck.com/advisories/mistune-3.3.0-before-3.3.4-quadratic-time-dos-via-process-emphasis-delimiters
- https://github.com/lepture/mistune/security/advisories/GHSA-qp42-r9j6-83g9
Source data: NVD (nvd.nist.gov), public domain. Exploit-DB.ai adds local AI analysis for defensive use only.
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