Saloon is a PHP library that gives users tools to build API integrations and SDKs. Prior to version 4.0.0, fixture names were used to build file paths under the configured fixture directory without validation. A name containing path segments (e.g. ../traversal or ../../etc/passwd) resulted in a path outside that directory. When the application read a fixture (e.g. for mocking) or wrote one (e.g. when recording responses), it could read or write files anywhere the process had access. If the fixtu