Artemis Java Test Sandbox versions before 1.8.0 are vulnerable to a sandbox escape when an attacker includes class files in a package that Ares trusts. An attacker can abuse this issue to execute arbitrary Java when a victim executes the supposedly sandboxed code.
https://vulncheck.com/advisories/vc-advisory-GHSA-227w-wv4j-67h4
https://github.com/ls1intum/Ares/security/advisories/GHSA-227w-wv4j-67h4
https://github.com/ls1intum/Ares/releases/tag/1.8.0