GHSA-9f2c-xxfm-32mj: Duplicate of GHSA-4xh4-v2pq-jvhm

The vulnerability centers around improper input validation of Swedish personal identity numbers. While no direct patch diffs are provided, multiple advisories explicitly state the root cause was a regex that allowed invalid last-four-digit patterns (^000[0-9]$). The primary validation function Personnummer.validate would be responsible for executing this regex check. In Dart implementations, this would typically be a static validation method in the Personnummer class. The function signature matches the entry point for number validation and would appear in stack traces when processing malicious inputs.