CVE-2026-121577 Unescaped header separators in whatstk build a regular expression that backtracks exponentially

Inefficient Regular Expression Complexity CWE-1333 in generateregex whatstk/whatsapp/parser.py in whatstk from 0.2.0 before 0.9.0 allows a party that supplies a chat export to consume the CPU of the process that parses it for an unbounded time, because the function builds the header regular...