A cache-based side channel in GnuTLS implementation that leads to plain text recovery in cross-VM attack setting was found. An attacker could use a combination of "Just in Time" Prime+probe attack in combination with Lucky-13 attack to recover plain text using crafted packets.
https://usn.ubuntu.com/3999-1/
https://lists.debian.org/debian-lts-announce/2018/10/msg00022.html
https://gitlab.com/gnutls/gnutls/merge_requests/657
https://eprint.iacr.org/2018/747
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-10846
https://access.redhat.com/errata/RHSA-2018:3505