CVE-2020-36400: Zeromq Libzmq

Critical severity, CVSS 9.8. EPSS: 1.8% chance of exploitation in the next 30 days.

ZeroMQ libzmq 4.3.3 has a heap-based buffer overflow in zmq::tcp_read, a different vulnerability than CVE-2021-20235.

Affected products

• Zeromq Libzmq: version 4.3.3 only

Published 2021-07-01. Last modified 2026-06-17.