This advisory announces multiple vulnerabilities in Jenkins, CloudBees Jenkins Platform and CloudBees Jenkins Solutions.
Sandbox Bypass in Script Security and Pipeline Groovy Plugins
SECURITY-1186
The Groovy Sandbox library used by Script Security Plugin and Pipeline Groovy Plugin did not apply sandbox restrictions to finalize methods. This could be used to invoke arbitrary constructors and methods, bypassing sandbox protection.
Finalize methods are now prohibited in classes subject to sandbox security.