PYSEC-2026-2651 Mistune has a ReDoS in LINK_TITLE_RE that allows denial of service via crafted Markdown input

Summary A ReDoS Regular Expression Denial of Service vulnerability in LINKTITLERE allows an attacker who can supply Markdown for parsing to cause denial of service. A crafted 58-byte Markdown document blocks the parser for approximately 6 seconds measured on Apple M2, Python 3.14.3, with...