In this blog post, critical security vulnerabilities discovered in Grav CMS are explored. Two out of four issues I reported have been assigned CVE-2024-27921 and CVE-2024-34082. By exploiting a combination of these vulnerabilities, an unauthenticated attacker can escalate privileges and execute code on the server. This blog post details how a manual source code review was performed to uncover these vulnerabilities, explaining their mechanisms and potential impact.