[[breaking-changes-6.2]]
== Breaking changes in 6.2

[[breaking_62_packaging]]
[float]
=== All permission bootstrap check

Elasticsearch installs a security manager during bootstrap to mitigate the scope
of exploits in the JDK, in third-party dependencies, and in Elasticsearch itself
as well as to sandbox untrusted plugins. A custom security policy can be applied
and one permission that can be added to this policy is
`java.security.AllPermission`. However, this effectively disables the security
manager. As such, granting this permission in production mode is now forbidden
via the <<all-permission-check, all permission bootstrap check>>.

[[breaking-changes-6.2]]
== Breaking changes in 6.2

[[breaking_62_packaging]]
[float]
=== All permission bootstrap check

Elasticsearch installs a security manager during bootstrap to mitigate the scope
of exploits in the JDK, in third-party dependencies, and in Elasticsearch itself
as well as to sandbox untrusted plugins. A custom security policy can be applied
and one permission that can be added to this policy is
`java.security.AllPermission`. However, this effectively disables the security
manager. As such, granting this permission in production mode is now forbidden
via the <<all-permission-check, all permission bootstrap check>>.

=== Private temporary directory

On Linux, previous versions of Elasticsearch defaulted to using `/tmp` as the
temporary directory for the process. However, `/tmp` is public so we have
elected to change the packaging so that we use a private temporary directory. If
you are upgrading from a previous version of Elasticsearch and preserve your
existing <<jvm-options,`jvm.options`>>, you should add the line
`-Djava.io.tmpdir=${ES_TMPDIR}`. It is safe to do this on all OS as we preserve
using a private temporary directory on non-Linux systems with the same
mechanism.

Add migration note on private temporary directory
Add migration note on private temporary directory

This commit adds a note to the migration docs on the packaging change to
always use a private temporary directory.

Relates #27624
