{"id":"CVE-2026-53996","state":"PUBLISHED","title":"NetBSD hdaudio(4) Driver Privilege Bypass Use-After-Free via HDAUDIO_FGRP_SETCONFIG ioctl","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.","publishedAt":"2026-08-12T12:42:33.380Z","updatedAt":"2026-08-14T16:50:18.508Z","severity":{"score":7.3,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["The NetBSD Foundation NetBSD"],"affected":[{"vendor":"The NetBSD Foundation","product":"NetBSD","defaultStatus":"affected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"11","versionType":"custom"}]}],"references":["https://gist.github.com/n4sm/c9683ca728ecfada6c726f2a5afb50ed","https://gnats.netbsd.org/60492","https://cvsweb.NetBSD.org/bsdweb.cgi/src/sys/dev/hdaudio/hdaudio.c","https://www.vulncheck.com/advisories/netbsd-hdaudio-4-driver-privilege-bypass-use-after-free-via-hdaudio-fgrp-setconfig-ioctl"],"weaknesses":["CWE-862"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53996.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53996","state":"PUBLISHED","datePublished":"2026-08-12T12:42:33.380Z","dateUpdated":"2026-08-14T16:50:18.508Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-06-11T16:07:13.001Z"},"containers":{"cna":{"title":"NetBSD hdaudio(4) Driver Privilege Bypass Use-After-Free via HDAUDIO_FGRP_SETCONFIG ioctl","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"The NetBSD Foundation","product":"NetBSD","defaultStatus":"affected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"11","versionType":"custom"}]}],"references":[{"url":"https://gist.github.com/n4sm/c9683ca728ecfada6c726f2a5afb50ed","name":"GitHub Gist","tags":["technical-description"]},{"url":"https://gnats.netbsd.org/60492","name":"Problem Report","tags":["issue-tracking"]},{"url":"https://cvsweb.NetBSD.org/bsdweb.cgi/src/sys/dev/hdaudio/hdaudio.c","name":"Fixed File","tags":["patch"]},{"url":"https://www.vulncheck.com/advisories/netbsd-hdaudio-4-driver-privilege-bypass-use-after-free-via-hdaudio-fgrp-setconfig-ioctl","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"LOCAL","attackComplexity":"HIGH","attackRequirements":"NONE","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"HIGH","baseScore":7.3,"vectorString":"CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}},{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"attackVector":"LOCAL","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","version":"3.1","baseSeverity":"HIGH","baseScore":7,"vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-862","lang":"en","description":"Missing Authorization","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-08-14T16:50:18.508Z"},"datePublic":"2026-08-12T00:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:netbsd:netbsd:*:*:*:*:*:*:*:*","versionEndIncluding":"11"}]}]}],"credits":[{"lang":"en","value":"Nasm","type":"finder"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"vulncheck"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-12T15:24:16.374511Z","id":"CVE-2026-53996","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-12T15:24:45.044Z"}}]}}}