Grav is a file-based Web platform. Prior to 1.8.0-beta.27, a Server-Side Template Injection (SSTI) vulnerability exists in Grav that allows authenticated attackers with editor permissions to execute arbitrary commands on the server and, under certain conditions, may also be exploited by unauthenticated attackers. This vulnerability stems from weak regex validation in the cleanDangerousTwig method. This vulnerability is fixed in 1.8.0-beta.27.

Grav is vulnerable to RCE via SSTI through Twig Sandbox Bypass