CVE-2016-1575
The overlayfs implementation in the Linux kernel through 4.5.2 does not properly maintain POSIX ACL xattr data, which allows local users to gain privileges by leveraging a group-writable setgid directory.
Date published : 2016-05-02
http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-1575.html