{"id":"CVE-2026-74531","state":"PUBLISHED","title":"Bluetooth: hci_conn: hold conn reference in abort_conn_sync()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_conn: hold conn reference in abort_conn_sync()\n\nThere is theoretical UAF if the conn is freed while the hci_sync task is\nrunning.\n\nHold refcount to avoid that.","publishedAt":"2026-08-15T12:27:45.988Z","updatedAt":"2026-10-16T19:05:53.525Z","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":"249c88e7fb45b6b705040c5af4bd0d0f2bc9735c","status":"affected","lessThan":"64d1645f26aa49b5a86ba2fccd0bb6749ea725a6","versionType":"git"},{"version":"227a0cdf4a028a73dc256d0f5144b4808d718893","status":"affected","lessThan":"963fb4b8e7d1ab07b4ae45bf15d41e667c88caca","versionType":"git"},{"version":"227a0cdf4a028a73dc256d0f5144b4808d718893","status":"affected","lessThan":"e8f9fef362bab431d95371d3406bc720350290c3","versionType":"git"},{"version":"227a0cdf4a028a73dc256d0f5144b4808d718893","status":"affected","lessThan":"fa812cfa81aa3d4a7b6ce8277979af57b3f79712","versionType":"git"},{"version":"227a0cdf4a028a73dc256d0f5144b4808d718893","status":"affected","lessThan":"5761d003daa987ac81463f570713ce9c9dd204e5","versionType":"git"},{"version":"7fe4d391e937c2f048a43ff4b421e677f10d83c0","status":"affected","versionType":"git"},{"version":"58afdc9b18871eb1d461c725be9e9f3f44a39aeb","status":"affected","versionType":"git"},{"version":"6.6.51","status":"affected","lessThan":"6.6.151","versionType":"semver"},{"version":"6.1.184","status":"affected","lessThan":"6.2","versionType":"semver"},{"version":"6.10.10","status":"affected","lessThan":"6.11","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_conn.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.11","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/hci_conn.c"]}],"references":["https://git.kernel.org/stable/c/64d1645f26aa49b5a86ba2fccd0bb6749ea725a6","https://git.kernel.org/stable/c/963fb4b8e7d1ab07b4ae45bf15d41e667c88caca","https://git.kernel.org/stable/c/e8f9fef362bab431d95371d3406bc720350290c3","https://git.kernel.org/stable/c/fa812cfa81aa3d4a7b6ce8277979af57b3f79712","https://git.kernel.org/stable/c/5761d003daa987ac81463f570713ce9c9dd204e5"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74531.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74531","state":"PUBLISHED","datePublished":"2026-08-15T12:27:45.988Z","dateUpdated":"2026-10-16T19:05:53.525Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.912Z"},"containers":{"cna":{"title":"Bluetooth: hci_conn: hold conn reference in abort_conn_sync()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_conn: hold conn reference in abort_conn_sync()\n\nThere is theoretical UAF if the conn is freed while the hci_sync task is\nrunning.\n\nHold refcount to avoid that."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"249c88e7fb45b6b705040c5af4bd0d0f2bc9735c","status":"affected","lessThan":"64d1645f26aa49b5a86ba2fccd0bb6749ea725a6","versionType":"git"},{"version":"227a0cdf4a028a73dc256d0f5144b4808d718893","status":"affected","lessThan":"963fb4b8e7d1ab07b4ae45bf15d41e667c88caca","versionType":"git"},{"version":"227a0cdf4a028a73dc256d0f5144b4808d718893","status":"affected","lessThan":"e8f9fef362bab431d95371d3406bc720350290c3","versionType":"git"},{"version":"227a0cdf4a028a73dc256d0f5144b4808d718893","status":"affected","lessThan":"fa812cfa81aa3d4a7b6ce8277979af57b3f79712","versionType":"git"},{"version":"227a0cdf4a028a73dc256d0f5144b4808d718893","status":"affected","lessThan":"5761d003daa987ac81463f570713ce9c9dd204e5","versionType":"git"},{"version":"7fe4d391e937c2f048a43ff4b421e677f10d83c0","status":"affected","versionType":"git"},{"version":"58afdc9b18871eb1d461c725be9e9f3f44a39aeb","status":"affected","versionType":"git"},{"version":"6.6.51","status":"affected","lessThan":"6.6.151","versionType":"semver"},{"version":"6.1.184","status":"affected","lessThan":"6.2","versionType":"semver"},{"version":"6.10.10","status":"affected","lessThan":"6.11","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_conn.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.11","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/hci_conn.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/64d1645f26aa49b5a86ba2fccd0bb6749ea725a6"},{"url":"https://git.kernel.org/stable/c/963fb4b8e7d1ab07b4ae45bf15d41e667c88caca"},{"url":"https://git.kernel.org/stable/c/e8f9fef362bab431d95371d3406bc720350290c3"},{"url":"https://git.kernel.org/stable/c/fa812cfa81aa3d4a7b6ce8277979af57b3f79712"},{"url":"https://git.kernel.org/stable/c/5761d003daa987ac81463f570713ce9c9dd204e5"}],"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 HCI connection abort path reachable when a nearby attacker sends connection, authentication-failure, or disconnect traffic that drives hci_disconnect()/hci_abort_conn() through hci_event processing.\nAC:L - An adjacent attacker can repeatedly initiate, fail, and tear down connections to race asynchronous abort_conn_sync work against hci_conn_del(), controlling both sides of the timing window without depending on uncontrollable system state.\nPR:N - Exploitation requires no local account or kernel privileges; a remote Bluetooth peer within RF range can trigger hci_abort_conn() via standard HCI event handling without authenticated pairing or CAP_NET_ADMIN access.\nUI:N - No deliberate victim action beyond normal Bluetooth availability is required; exploitation works against discoverable/connectable devices and already-paired reconnections without opening files or confirming a one-off prompt.\nS:U - Impact is kernel heap corruption and potential privilege escalation within the host kernel security boundary, not a cross-boundary escape such as VM guest-to-host or IOMMU bypass.\nC:H - Use-after-free of struct hci_conn lets an attacker read freed slab memory through abort_conn_sync/hci_abort_conn_sync field accesses, enabling disclosure of kernel pointers and adjacent heap contents.\nI:H - UAF of hci_conn is heap memory corruption that can be shaped via slab reuse and exploited for arbitrary kernel writes or control-flow hijack, not merely a bounded data change.\nA:H - Accessing a freed hci_conn during abort_conn_sync can cause kernel oops, BUG, or panic, and UAF corruption can crash or hang the system even when full exploitation is not 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