CVE-2014-9721: Zeromq

Medium severity, CVSS 4.3. EPSS: 2.5% chance of exploitation in the next 30 days.

libzmq before 4.0.6 and 4.1.x before 4.1.1 allows remote attackers to conduct downgrade attacks and bypass ZMTP v3 protocol security mechanisms via a ZMTP v2 or earlier header.

Affected products

• Zeromq Zeromq: up to and including 4.0.5; version 4.1.0 only

Published 2015-06-03. Last modified 2026-06-17.