{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74534", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.913Z", "datePublished": "2026-08-15T12:27:47.831Z", "dateUpdated": "2026-08-17T05:48:23.337Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:48:23.337Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: ISO: fix refcounting of iso_conn\n\niso_conn_del() and iso_chan_del() have a race that results to double-put\nof iso_conn:\n\n [Task hdev->workqueue] [Task 2]\n iso_conn_del iso_chan_del\n iso_conn_hold_unless_zero iso_conn_lock\n iso_conn_lock conn->sk = NULL\n iso_conn_unlock\n sk = iso_sock_hold(conn) <---------ยด\n if (!sk) iso_conn_put iso_conn_put\n iso_conn_put /* UAF */\n\nThe extra put for !sk in iso_conn_del() is currently required since\nfailing iso_chan_add() may leave iso_conn not associated with any sk.\n\nFix by having iso_pi(sk)->conn own refcount when non-NULL, so\niso_conn_del does not need to put it. Adjust the iso_conn_add()\nrefcounting so that conn is put if it does not get associated with an\nsk." } ], "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 bug is in Bluetooth ISO connection teardown; a remote LE Audio/CIS/BIS peer in range can trigger iso_conn_del via HCI disconnect events (iso_disconn_cfm) that race with concurrent socket teardown.\nAC:L - The double kref_put race is between iso_conn_del and iso_chan_del; an adjacent attacker controls disconnect timing and can repeatedly connect/disconnect to race automatic kernel and Bluetooth daemon socket cleanup.\nPR:N - No local UNIX privileges are required; a malicious or compromised adjacent Bluetooth ISO peer with an established connection can initiate the disconnect leg without root, capabilities, or user-namespace admin rights.\nUI:N - No explicit victim action is needed beyond an active ISO session; remote disconnect triggers automatic HCI teardown and stack socket close that can race iso_chan_del without the user manually closing applications.\nS:U - The vulnerability corrupts kernel heap lifetime of iso_conn objects within the Bluetooth subsystem and does not cross VM, hypervisor, or IOMMU security boundaries.\nC:H - Premature kfree of iso_conn from the refcount race is a use-after-free that can expose kernel heap contents and be leveraged for arbitrary kernel memory disclosure.\nI:H - UAF on iso_conn enables heap grooming and corrupted pointer dereferences that can be leveraged for arbitrary kernel memory writes or privilege-escalating code execution.\nA:H - The double iso_conn_put can free iso_conn while still referenced, causing kernel oops/panic or reliably exploitable instability during ISO connection teardown." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bluetooth/iso.c" ], "versions": [ { "version": "dc26097bdb864a0d5955b9a25e43376ffc1af99b", "lessThan": "3b921533e8aa95b77aadcf31737595578e735f3c", "status": "affected", "versionType": "git" }, { "version": "dc26097bdb864a0d5955b9a25e43376ffc1af99b", "lessThan": "8208b4939afb0a1977fffe902c3ca42fe0f3baaa", "status": "affected", "versionType": "git" }, { "version": "dc26097bdb864a0d5955b9a25e43376ffc1af99b", "lessThan": "fdfde532ab1caa165fcd8985001157ac8b4db365", "status": "affected", "versionType": "git" }, { "version": "f53e7489273dc2bb307bf50f319b3762d45534f0", "status": "affected", "versionType": "git" }, { "version": "a58d0f5dac322e16cc75334d000666512341bde5", "status": "affected", "versionType": "git" }, { "version": "6.11.11", "lessThan": "6.12", "status": "affected", "versionType": "semver" }, { "version": "6.12.2", "lessThan": "6.13", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bluetooth/iso.c" ], "versions": [ { "version": "6.13", "status": "affected" }, { "version": "0", "lessThan": "6.13", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.44", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.8", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.44" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "7.1.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/3b921533e8aa95b77aadcf31737595578e735f3c" }, { "url": "https://git.kernel.org/stable/c/8208b4939afb0a1977fffe902c3ca42fe0f3baaa" }, { "url": "https://git.kernel.org/stable/c/fdfde532ab1caa165fcd8985001157ac8b4db365" } ], "title": "Bluetooth: ISO: fix refcounting of iso_conn", "x_generator": { "engine": "bippy-1.2.0" } } } }