Worked on the laravel/framework repository to enhance the security and reliability of attachment URL handling by implementing strict URL scheme validation in the Attachment::fromUrl() method. This update ensures that only http and https schemes are accepted, while invalid schemes are properly rejected, reducing the risk of unsafe attachments and improving data integrity. The approach included adding comprehensive regression tests to verify both valid and invalid scenarios, thereby increasing test coverage and input validation. The work was carried out using PHP and the Laravel framework, with PHPUnit employed for testing, and followed modern Git-based development workflows to maintain code quality.