CVE-2009-4027: Linux Kernel

High severity, CVSS 7.1. EPSS: 2.3% chance of exploitation in the next 30 days.

Race condition in the mac80211 subsystem in the Linux kernel before 2.6.32-rc8-next-20091201 allows remote attackers to cause a denial of service (system crash) via a Delete Block ACK (aka DELBA) packet that triggers a certain state change in the absence of an aggregation session.

Affected products

• Linux Linux Kernel: up to and including 2.6.32; version 2.6.0 only; version 2.6.1 only; version 2.6.2 only; version 2.6.3 only; version 2.6.4 only; …

Published 2009-12-02. Last modified 2026-06-16.