NetBSD up to 11 hdaudio hdaudio.c hdafg_detach use after free

Summaryinfo

A vulnerability was found in NetBSD up to 11 and classified as very critical. Affected by this issue is the function hdafg_detach of the file sys/dev/hdaudio/hdaudio.c of the component hdaudio. Such manipulation leads to use after free. This vulnerability is traded as CVE-2026-53996. An attack has to be approached locally. There is no exploit available.

Detailsinfo

A vulnerability was found in NetBSD up to 11 and classified as very critical. Affected by this issue is the function hdafg_detach of the file sys/dev/hdaudio/hdaudio.c of the component hdaudio. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at gist.github.com. This vulnerability is handled as CVE-2026-53996 since 06/11/2026. The exploitation is known to be easy. Local access is required to approach this attack. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 08/12/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Operating System

Name

• NetBSD

Version

• 11

License

• open-source

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Discussion