GHSA-957R-QF9P-67XW Craft CMS: Arbitrary file read via SplFileObject in non-sandboxed template contexts

The create Twig function introduced in 5.9.0 allows instantiation of arbitrary PHP classes from template code, restricted only by a 5-entry blocklist. SplFileObject is not in the blocklist, enabling arbitrary file read, including .env security key, DB credentials and the passwd file from...