runc through 1.0.0-rc9 has Incorrect Access Control leading to Escalation of Privileges, related to libcontainer/rootfs_linux.go. To exploit this, an attacker must be able to spawn two containers with custom volume-mount configurations, and be able to run custom images. (This vulnerability does not affect Docker due to an implementation detail that happens to block the attack.)
https://usn.ubuntu.com/4297-1/
https://security.gentoo.org/glsa/202003-21
https://security-tracker.debian.org/tracker/CVE-2019-19921
https://lists.debian.org/debian-lts-announce/2023/03/msg00023.html
https://github.com/opencontainers/runc/releases
https://github.com/opencontainers/runc/pull/2190
https://github.com/opencontainers/runc/issues/2197
https://access.redhat.com/errata/RHSA-2020:0695
https://access.redhat.com/errata/RHSA-2020:0688
http://lists.opensuse.org/opensuse-security-announce/2020-02/msg00018.html