symfony/validator is a module for the Symphony PHP framework which provides tools to validate values. It is possible to trick a "Validator" configured with a regular expression using the "$" metacharacters, with an input ending with "\n". Symfony as of versions 5.4.43, 6.4.11, and 7.1.4 now uses the "D" regex modifier to match the entire input. Users are advised to upgrade. There are no known workarounds for this vulnerability.