NetBSD hdaudio(4) Driver Privilege Bypass Use-After-Free via HDAUDIO_FGRP_SETCONFIG ioctl (CVE-2026-53996) | HOL Guard CVE

High · CVSS 7.3CVE-2026-53996

NetBSD hdaudio(4) Driver Privilege Bypass Use-After-Free via HDAUDIO_FGRP_SETCONFIG ioctl

Answer in brief

CVE-2026-53996 records a High severity (CVSS 7.3) vulnerability in NetBSD hdaudio(4) Driver Privilege Bypass Use-After-Free via HDAUDIO_FGRP_SETCONFIG ioctl. The current sources do not mark it as known exploited. The current feed maps The NetBSD Foundation/NetBSD (generic), The NetBSD Foundation/NetBSD (generic), The NetBSD Foundation/NetBSD (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 12, 2026Updated Aug 14, 2026Source checked Sep 26, 2026First seen by HOL Aug 12, 2026Material review Aug 14, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.3
Exploitation: Not marked as known exploited
Affected software: 3 mapped packages or products
Fix availability: Not reported

Why this deserves its current priority

CVSS is 7.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps The NetBSD Foundation/NetBSD (generic), The NetBSD Foundation/NetBSD (generic), The NetBSD Foundation/NetBSD (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
The NetBSD Foundation/NetBSDgeneric	0	Not reported
The NetBSD Foundation/NetBSDgeneric	>=0 <=11	Not reported
The NetBSD Foundation/NetBSDgeneric	*	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for The NetBSD Foundation/NetBSD, The NetBSD Foundation/NetBSD, The NetBSD Foundation/NetBSD.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 12, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 12, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.