CVE-2026-53996: NetBSD hdaudio(4) Driver Privilege Bypass Use-After-Free via HDAUDIO_FGRP_SETCONFIG ioctl
NetBSD's hdaudio(4) driver in sys/dev/hdaudio/hdaudio.c contains a missing access control vulnerability that allows unprivileged local attackers to invoke the HDAUDIOFGRPSETCONFIG ioctl without elevated permissions by exploiting the absence of an access check on /dev/hdaudioN device nodes. Attackers can repeatedly issue HDAUDIOFGRPSETCONFIG from one thread while keeping DMA and IRQs live from a second thread to trigger a use-after-free race condition in hdafgdetach() between streamstop() and streamdisestablish(), where a latched DMA interrupt dereferences a freed callback pointer, resulting in outcomes ranging from audio-subsystem denial of service and kernel panic to potential local kernel privilege escalation.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-53996?
The severity of CVE-2026-53996 is high with a score of 7.
How does CVE-2026-53996 affect system security?
CVE-2026-53996 allows unprivileged local attackers to exploit the hdaudio driver without elevated permissions, compromising system security.
How do I fix CVE-2026-53996?
To fix CVE-2026-53996, ensure that you apply the latest patches from NetBSD that address the missing access control vulnerability.
What types of attacks can be executed using CVE-2026-53996?
CVE-2026-53996 can be exploited to perform privilege bypass attacks through improper access control on /dev/hdaudioN device nodes.
What are the main vulnerabilities associated with CVE-2026-53996?
CVE-2026-53996 is associated with the 'Use After Free' and 'Race Condition' vulnerabilities.