CVE-2021-20203: Debian Linux

Low severity, CVSS 3.2. EPSS: 0.6% chance of exploitation in the next 30 days.

An integer overflow issue was found in the vmxnet3 NIC emulator of the QEMU for versions up to v5.2.0. It may occur if a guest was to supply invalid values for rx/tx queue size or other NIC parameters. A privileged guest user may use this flaw to crash the QEMU process on the host resulting in DoS scenario.

Affected products

• Debian Debian Linux: version 9.0 only; version 10.0 only
• Fedoraproject Fedora: version 33 only
• Qemu Qemu: up to and including 5.2.0

Published 2021-02-25. Last modified 2026-06-17.