SecureProps is a PHP library designed to simplify the encryption and decryption of property data in objects. A vulnerability in SecureProps version 1.2.0 and 1.2.1 involves a regex failing to detect tags during decryption of encrypted data. This occurs when the encrypted data has been encoded with "NullEncoder" and passed to "TagAwareCipher", and contains special characters such as "\n". As a result, the decryption process is skipped since the tags are not detected. This causes the encrypted data to be returned in plain format. The vulnerability affects users who implement "TagAwareCipher" with any base cipher that has "NullEncoder" (not default). The patch for the issue has been released. Users are advised to update to version 1.2.2. As a workaround, one may use the default "Base64Encoder" with the base cipher decorated with "TagAwareCipher" to prevent special characters in the encrypted string from interfering with regex tag detection logic. This workaround is safe but may involve double encoding since "TagAwareCipher" uses "NullEncoder" by default.