It was found that the use of Pipeline: Classpath Step Jenkins plugin enables a bypass of the Script Security sandbox for users with SCM commit access, as well as users with e.g. Job/Configure permission in Jenkins.
[
{
"product": "Pipeline: Classpath Step Jenkins plugin",
"vendor": "Jenkins project",
"versions": [
{
"status": "affected",
"version": "all"
}
]
}
]