CVE-2018-12434: OpenBSD Libressl

Medium severity, CVSS 4.7. EPSS: 0.3% chance of exploitation in the next 30 days.

LibreSSL before 2.6.5 and 2.7.x before 2.7.4 allows a memory-cache side-channel attack on DSA and ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover a key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.

Affected products

• OpenBSD Libressl: before 2.6.5 (fixed in 2.6.5); version 2.7.0 only; version 2.7.1 only; version 2.7.2 only; version 2.7.3 only

Published 2018-06-15. Last modified 2026-06-17.