A critical authorization bypass vulnerability in Arcane, a Docker container management interface, allows authenticated non-admin users to overwrite global environment variables via the PUT /api/environments/{id}/templates/variables endpoint. Attackers can exploit this to redirect image pulls to malicious registries, enabling supply-chain attacks and remote code execution on Docker hosts. The vulnerability also allows credential exfiltration and disruption of all projects by manipulating variables like REGISTRY, IMAGE, DATABASE_URL, and SECRET_KEY. This affects all versions prior to 1.19.2, which contains the fix.