Simultaneous Multi-threading (SMT) in processors can enable local users to exploit software vulnerable to timing attacks via a side-channel timing attack on 'port contention'.
https://www.tenable.com/security/tns-2018-17
https://www.tenable.com/security/tns-2018-16
https://www.oracle.com/technetwork/security-advisory/cpujul2019-5072835.html
https://www.oracle.com/technetwork/security-advisory/cpujan2019-5072801.html
https://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.html
https://www.oracle.com/security-alerts/cpujan2020.html
https://www.oracle.com/security-alerts/cpuapr2020.html
https://www.exploit-db.com/exploits/45785/
https://www.debian.org/security/2018/dsa-4355
https://www.debian.org/security/2018/dsa-4348
https://usn.ubuntu.com/3840-1/
https://support.f5.com/csp/article/K49711130?utm_source=f5support&%3Butm_medium=RSS
https://security.netapp.com/advisory/ntap-20181126-0001/
https://security.gentoo.org/glsa/201903-10
https://nodejs.org/en/blog/vulnerability/november-2018-security-releases/
https://lists.debian.org/debian-lts-announce/2018/11/msg00024.html
https://github.com/bbbrumley/portsmash
https://eprint.iacr.org/2018/1060.pdf
https://access.redhat.com/errata/RHSA-2019:3935
https://access.redhat.com/errata/RHSA-2019:3933
https://access.redhat.com/errata/RHSA-2019:3932
https://access.redhat.com/errata/RHSA-2019:3931
https://access.redhat.com/errata/RHSA-2019:3929
https://access.redhat.com/errata/RHSA-2019:2125
https://access.redhat.com/errata/RHSA-2019:0652
https://access.redhat.com/errata/RHSA-2019:0651