CVE-2026-53996 NetBSD hdaudio(4) Driver Privilege Bypass Use-After-Free via HDAUDIO_FGRP_SETCONFIG ioctl
Unprivileged local attackers can trigger a use-after-free race condition in the NetBSD hdaudio driver, potentially leading to kernel privilege escalation or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-53996?
CVE-2026-53996 is a high-severity use after free vulnerability in The NetBSD Foundation NetBSD, published on 12 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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 HDAUDIO_FGRP_SETCONFIG ioctl without elevated permissions by exploiting the absence of an access check on /dev/hdaudioN device nodes. Attackers can repeatedly issue HDAUDIO_FGRP_SETCONFIG from one thread while keeping DMA and IRQs live from a second thread to trigger a use-after-free race condition in hdafg_detach() between stream_stop() and stream_disestablish(), 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.
Weakness: CWE-862
Which versions are affected by CVE-2026-53996?
How do I fix CVE-2026-53996?
No fix has been published for CVE-2026-53996 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-53996 being exploited?
There is no known exploitation of CVE-2026-53996 in the wild and no public exploit code.
Sources
Also known as GHSA-2q5f-pw9r-2w7m.