CVE-2019-6250: Debian Linux

High severity, CVSS 8.8. EPSS: 9.7% chance of exploitation in the next 30 days.

A pointer overflow, with code execution, was discovered in ZeroMQ libzmq (aka 0MQ) 4.2.x and 4.3.x before 4.3.1. A v2_decoder.cpp zmq::v2_decoder_t::size_ready integer overflow allows an authenticated attacker to overwrite an arbitrary amount of bytes beyond the bounds of a buffer, which can be leveraged to run arbitrary code on the target system. The memory layout allows the attacker to inject OS commands into a data structure located immediately after the problematic buffer (i.e., it is not necessary to use a typical buffer-overflow exploitation technique that changes the flow of control).

Affected products

• Debian Debian Linux: version 9.0 only
• Zeromq Libzmq: from 4.2.0, up to and including 4.2.5; from 4.3.0, before 4.3.1 (fixed in 4.3.1)

Published 2019-01-13. Last modified 2026-06-17.