Libgcrypt before 1.7.10 and 1.8.x before 1.8.3 allows a memory-cache side-channel attack on ECDSA signatures that can be mitigated through the use of blinding during the signing process in the _gcry_ecc_ecdsa_sign function in cipher/ecc-ecdsa.c, aka the Return Of the Hidden Number Problem or ROHNP. To discover an ECDSA key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.
https://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.html
https://www.nccgroup.trust/us/our-research/technical-advisory-return-of-the-hidden-number-problem/
https://www.debian.org/security/2018/dsa-4231
https://usn.ubuntu.com/3850-2/
https://usn.ubuntu.com/3850-1/
https://usn.ubuntu.com/3692-2/
https://usn.ubuntu.com/3692-1/
https://usn.ubuntu.com/3689-2/
https://usn.ubuntu.com/3689-1/
https://lists.gnupg.org/pipermail/gnupg-announce/2018q2/000426.html
https://lists.debian.org/debian-lts-announce/2018/06/msg00013.html
https://access.redhat.com/errata/RHSA-2019:2237
https://access.redhat.com/errata/RHSA-2019:1543
https://access.redhat.com/errata/RHSA-2019:1297
https://access.redhat.com/errata/RHSA-2019:1296
https://access.redhat.com/errata/RHSA-2018:3505
https://access.redhat.com/errata/RHSA-2018:3221