{"id":"CVE-2026-74530","state":"PUBLISHED","title":"Bluetooth: hci_sync: hold conn in hci_connect_big_sync() callback","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: hold conn in hci_connect_big_sync() callback\n\nThere is theoretical UAF if the conn is freed while the hci_sync task is\nrunning.\n\nHold refcount to avoid that. Handle NULL hcon, return 0 + do nothing to\nmatch the previous behavior.","publishedAt":"2026-08-15T12:27:45.381Z","updatedAt":"2026-10-21T12:45:48.364Z","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":"620810ac1f7f1133a9ac403e132b3ad6995ddf39","status":"affected","lessThan":"117d8bcaf1abc348185e8ab6a4ba9f8f516849a0","versionType":"git"},{"version":"024421cf39923927ab2b5fe895d1d922b9abe67f","status":"affected","lessThan":"ff5625d27415ace5667bf87ebc16c3a0a98db22f","versionType":"git"},{"version":"024421cf39923927ab2b5fe895d1d922b9abe67f","status":"affected","lessThan":"2d91e6244b69d752503b2d44020d8b0e323dbd38","versionType":"git"},{"version":"024421cf39923927ab2b5fe895d1d922b9abe67f","status":"affected","lessThan":"56e78b670356caab0b607e8aad4cf819a1909d07","versionType":"git"},{"version":"ee0586ad64a805eaf1a9a10100e908627a561e34","status":"affected","versionType":"git"},{"version":"6.12.28","status":"affected","lessThan":"6.12.114","versionType":"semver"},{"version":"6.14.6","status":"affected","lessThan":"6.15","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_sync.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.15","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","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_sync.c"]}],"references":["https://git.kernel.org/stable/c/117d8bcaf1abc348185e8ab6a4ba9f8f516849a0","https://git.kernel.org/stable/c/ff5625d27415ace5667bf87ebc16c3a0a98db22f","https://git.kernel.org/stable/c/2d91e6244b69d752503b2d44020d8b0e323dbd38","https://git.kernel.org/stable/c/56e78b670356caab0b607e8aad4cf819a1909d07"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74530.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74530","state":"PUBLISHED","datePublished":"2026-08-15T12:27:45.381Z","dateUpdated":"2026-10-21T12:45:48.364Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.912Z"},"containers":{"cna":{"title":"Bluetooth: hci_sync: hold conn in hci_connect_big_sync() callback","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: hold conn in hci_connect_big_sync() callback\n\nThere is theoretical UAF if the conn is freed while the hci_sync task is\nrunning.\n\nHold refcount to avoid that. Handle NULL hcon, return 0 + do nothing to\nmatch the previous behavior."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"620810ac1f7f1133a9ac403e132b3ad6995ddf39","status":"affected","lessThan":"117d8bcaf1abc348185e8ab6a4ba9f8f516849a0","versionType":"git"},{"version":"024421cf39923927ab2b5fe895d1d922b9abe67f","status":"affected","lessThan":"ff5625d27415ace5667bf87ebc16c3a0a98db22f","versionType":"git"},{"version":"024421cf39923927ab2b5fe895d1d922b9abe67f","status":"affected","lessThan":"2d91e6244b69d752503b2d44020d8b0e323dbd38","versionType":"git"},{"version":"024421cf39923927ab2b5fe895d1d922b9abe67f","status":"affected","lessThan":"56e78b670356caab0b607e8aad4cf819a1909d07","versionType":"git"},{"version":"ee0586ad64a805eaf1a9a10100e908627a561e34","status":"affected","versionType":"git"},{"version":"6.12.28","status":"affected","lessThan":"6.12.114","versionType":"semver"},{"version":"6.14.6","status":"affected","lessThan":"6.15","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/hci_sync.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.15","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","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_sync.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/117d8bcaf1abc348185e8ab6a4ba9f8f516849a0"},{"url":"https://git.kernel.org/stable/c/ff5625d27415ace5667bf87ebc16c3a0a98db22f"},{"url":"https://git.kernel.org/stable/c/2d91e6244b69d752503b2d44020d8b0e323dbd38"},{"url":"https://git.kernel.org/stable/c/56e78b670356caab0b607e8aad4cf819a1909d07"}],"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 LE ISO BIG Create Sync handling (hci_connect_big_sync), reachable via adjacent BLE traffic that drives HCI events (e.g. HCI_EVT_LE_BIG_INFO_ADV_REPORT through iso_connect_ind) and via local ISO sockets; Bluetooth kernel bugs are scored as Adjacent, not Network.\nAC:L - After 024421cf3992 the path blocks in __hci_cmd_sync_status_sk for up to conn_timeout while only holding a bare hci_conn pointer; an attacker who can open/close an ISO broadcast socket (or race teardown during that wait) controls both sides of the race and can reliably trigger the UAF.\nPR:N - Exploitation does not require root or CAP_NET_ADMIN; adjacent attackers can trigger the vulnerable code through unauthenticated over-the-air BLE broadcasts processed by the kernel HCI layer, and local exploitation only needs standard Bluetooth/ISO socket access available to unprivileged users/apps with Bluetooth permission.\nUI:N - No victim interaction is required beyond attacker-controlled actions such as creating an ISO broadcast listener socket, starting BIG sync, and concurrently closing the socket to free hci_conn while hci_sync work is still running; exploitation does not depend on another user opening files or mounting resources.\nS:U - The use-after-free corrupts kernel heap memory within the Bluetooth/hci_conn subsystem and can lead to local privilege escalation, but it does not cross a VM, IOMMU, or sandbox security boundary into another authority domain.\nC:H - This is a kernel heap use-after-free of struct hci_conn; freed connection objects can be reallocated and read through subsequent dereferences in create_big_complete and hci_le_big_create_sync, providing a standard path to arbitrary kernel memory disclosure.\nI:H - UAF on struct hci_conn allows corrupting connection flags and adjacent heap contents; the structure contains function pointers (cleanup, connect_cfm_cb, disconn_cfm_cb) and is large enough to support heap grooming toward arbitrary write or control-flow hijack.\nA:H - Use-after-free during clear_bit on conn->flags in create_big_complete, or accessing conn fields after teardown during the blocking BIG sync command, can cause kernel oops/panic and repeated disruption; UAF availability impact is rated High per kernel guidance."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-21T12:45:48.364Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.28","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"6.18.57"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.1.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14.6"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-74530","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T18:59:16.031043Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T19:05:53.346Z"}}]}}}