CVE-2026-59922: Python Markdown Quadratic Regex Markercve-2026-59922-python-markdown-quadratic-regex-marker
Regular expressions using negative lookaheads for markdown text markers (e.g., `~~(?!~)`) can bypass intermediate boundaries in heavily chained contiguous token sequences. In a recursive descent parser, this collapse forces the engine to parse large blocks recursively, leading to O(N^2) CPU exhaustion DoS. Use iterative string search (`str.find`) with manual
