{"id":"CVE-2026-74541","state":"PUBLISHED","title":"Bluetooth: ISO: clear iso_data always when detaching conn from hcon","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: ISO: clear iso_data always when detaching conn from hcon\n\nWhen setting conn->hcon = NULL, also conn->hcon->iso_data = NULL is\nnecessary, otherwise later iso_conn_free() will UAF.\n\nFix clearing of iso_data in iso_sock_disconn()\n\nFixes KASAN: slab-use-after-free in iso_conn_hold_unless_zero on\niso_sock_release() followed by hci_abort_conn_sync().","publishedAt":"2026-08-15T12:27:52.120Z","updatedAt":"2026-10-16T19:05:54.748Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"fbdc4bc47268953c80853489f696e02d61f9a2c6","status":"affected","lessThan":"cc1d39946d62bc568551dfb81149724de1e91338","versionType":"git"},{"version":"fbdc4bc47268953c80853489f696e02d61f9a2c6","status":"affected","lessThan":"7b51a9c25e9698b64df9f2218f10eecf7dc7e2d0","versionType":"git"},{"version":"fbdc4bc47268953c80853489f696e02d61f9a2c6","status":"affected","lessThan":"63c0f396a18b767eb28e895eb95bbdce6c172c59","versionType":"git"},{"version":"fbdc4bc47268953c80853489f696e02d61f9a2c6","status":"affected","lessThan":"69a4a7b162b3db6ac337e3094cdee38f24d42ff7","versionType":"git"},{"version":"fbdc4bc47268953c80853489f696e02d61f9a2c6","status":"affected","lessThan":"d57e506f6a1e3929611340fae87c1e4823f4d85c","versionType":"git"},{"version":"c03a10bd5b6ccb22921e04bcddc987410df7e7a9","status":"affected","versionType":"git"},{"version":"6.5.12","status":"affected","lessThan":"6.6","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/iso.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.6","versionType":"semver"},{"version":"6.6.151","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.103","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.44","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.8","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/iso.c"]}],"references":["https://git.kernel.org/stable/c/cc1d39946d62bc568551dfb81149724de1e91338","https://git.kernel.org/stable/c/7b51a9c25e9698b64df9f2218f10eecf7dc7e2d0","https://git.kernel.org/stable/c/63c0f396a18b767eb28e895eb95bbdce6c172c59","https://git.kernel.org/stable/c/69a4a7b162b3db6ac337e3094cdee38f24d42ff7","https://git.kernel.org/stable/c/d57e506f6a1e3929611340fae87c1e4823f4d85c"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74541.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74541","state":"PUBLISHED","datePublished":"2026-08-15T12:27:52.120Z","dateUpdated":"2026-10-16T19:05:54.748Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.914Z"},"containers":{"cna":{"title":"Bluetooth: ISO: clear iso_data always when detaching conn from hcon","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: ISO: clear iso_data always when detaching conn from hcon\n\nWhen setting conn->hcon = NULL, also conn->hcon->iso_data = NULL is\nnecessary, otherwise later iso_conn_free() will UAF.\n\nFix clearing of iso_data in iso_sock_disconn()\n\nFixes KASAN: slab-use-after-free in iso_conn_hold_unless_zero on\niso_sock_release() followed by hci_abort_conn_sync()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"fbdc4bc47268953c80853489f696e02d61f9a2c6","status":"affected","lessThan":"cc1d39946d62bc568551dfb81149724de1e91338","versionType":"git"},{"version":"fbdc4bc47268953c80853489f696e02d61f9a2c6","status":"affected","lessThan":"7b51a9c25e9698b64df9f2218f10eecf7dc7e2d0","versionType":"git"},{"version":"fbdc4bc47268953c80853489f696e02d61f9a2c6","status":"affected","lessThan":"63c0f396a18b767eb28e895eb95bbdce6c172c59","versionType":"git"},{"version":"fbdc4bc47268953c80853489f696e02d61f9a2c6","status":"affected","lessThan":"69a4a7b162b3db6ac337e3094cdee38f24d42ff7","versionType":"git"},{"version":"fbdc4bc47268953c80853489f696e02d61f9a2c6","status":"affected","lessThan":"d57e506f6a1e3929611340fae87c1e4823f4d85c","versionType":"git"},{"version":"c03a10bd5b6ccb22921e04bcddc987410df7e7a9","status":"affected","versionType":"git"},{"version":"6.5.12","status":"affected","lessThan":"6.6","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/iso.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.6","versionType":"semver"},{"version":"6.6.151","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.103","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.44","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.8","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/iso.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/cc1d39946d62bc568551dfb81149724de1e91338"},{"url":"https://git.kernel.org/stable/c/7b51a9c25e9698b64df9f2218f10eecf7dc7e2d0"},{"url":"https://git.kernel.org/stable/c/63c0f396a18b767eb28e895eb95bbdce6c172c59"},{"url":"https://git.kernel.org/stable/c/69a4a7b162b3db6ac337e3094cdee38f24d42ff7"},{"url":"https://git.kernel.org/stable/c/d57e506f6a1e3929611340fae87c1e4823f4d85c"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:A - The flaw is in the Bluetooth ISO stack (net/bluetooth/iso.c); exploitation occurs during ISO connection teardown reachable from adjacent Bluetooth LE Audio/CIS/BIS deployments on phones, laptops, and embedded systems where ISO HCI traffic is processed wirelessly.\nAC:L - The KASAN reproducer (iso_sock_release() then hci_abort_conn_sync()) is reliably triggered by closing an ISO socket while hci_conn_drop() runs; the attacker controls both the socket lifecycle and concurrent teardown timing without depending on uncontrollable memory layout.\nPR:N - AF_BLUETOOTH/BTPROTO_ISO sockets require no CAP_NET_ADMIN or CAP_NET_RAW; any unprivileged process in init_net can open, connect, and close ISO sockets, and adjacent Bluetooth peers can also dereference the stale hcon->iso_data via iso_recv() without host credentials.\nUI:N - No victim interaction is required when a malicious or compromised local process creates and closes its own ISO connection to trigger iso_sock_disconn(); exploitation does not depend on mounting filesystems or opening specific user files.\nS:U - The UAF corrupts kernel heap memory during ISO connection teardown, enabling standard local privilege escalation within the kernel security boundary rather than crossing VM, container, or IOMMU isolation boundaries.\nC:H - iso_conn_hold_unless_zero() performs kref_get_unless_zero() on a freed iso_conn slab object, a classic use-after-free that can expose adjacent kernel heap contents and be leveraged for arbitrary kernel memory disclosure.\nI:H - The UAF on iso_conn (containing kref, spinlock, and socket pointers) enables heap spraying and memory corruption primitives that can be chained for arbitrary kernel writes and control-flow hijacking.\nA:H - The bug was confirmed by KASAN as a slab use-after-free in iso_conn_hold_unless_zero during ISO socket release and hci_abort_conn_sync(), which causes kernel oops or panic and denial of service on affected systems."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T05:48:29.921Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"6.6.151"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"6.12.103"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"6.18.44"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"7.1.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"7.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5.12"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-74541","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T18:59:46.525127Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T19:05:54.748Z"}}]}}}