{"id":"CVE-2026-43019","state":"PUBLISHED","title":"Bluetooth: hci_conn: fix potential UAF in set_cig_params_sync","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_conn: fix potential UAF in set_cig_params_sync\n\nhci_conn lookup and field access must be covered by hdev lock in\nset_cig_params_sync, otherwise it's possible it is freed concurrently.\n\nTake hdev lock to prevent hci_conn from being deleted or modified\nconcurrently.  Just RCU lock is not suitable here, as we also want to\navoid \"tearing\" in the configuration.","publishedAt":"2026-05-01T14:15:23.035Z","updatedAt":"2026-10-19T19:06:09.770Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/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":"a091289218202bc09d9b9caa8afcde1018584aec","status":"affected","lessThan":"7502c1cf303b69f71d085f5ff7251b0e1b0f09df","versionType":"git"},{"version":"a091289218202bc09d9b9caa8afcde1018584aec","status":"affected","lessThan":"66d432e9b45bae7881ffcdb12cd8fd0bf254ef02","versionType":"git"},{"version":"a091289218202bc09d9b9caa8afcde1018584aec","status":"affected","lessThan":"7d568fede8eac91161a60b710aa920abe9b0fb9f","versionType":"git"},{"version":"a091289218202bc09d9b9caa8afcde1018584aec","status":"affected","lessThan":"bad65b4b0a96139f023eadc28a33125963208449","versionType":"git"},{"version":"a091289218202bc09d9b9caa8afcde1018584aec","status":"affected","lessThan":"a2639a7f0f5bf7d73f337f8f077c19415c62ed2c","versionType":"git"},{"version":"3a273cd0f47dd672d37736e623849374f9ab9ce9","status":"affected","versionType":"git"},{"version":"d8570c4c3f2a3e51b3c8b5e6ec898364c5c03062","status":"affected","versionType":"git"},{"version":"6.4.16","status":"affected","lessThan":"6.5","versionType":"semver"},{"version":"6.5.3","status":"affected","lessThan":"6.6","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":"6.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.6","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.81","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.22","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.12","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","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/7502c1cf303b69f71d085f5ff7251b0e1b0f09df","https://git.kernel.org/stable/c/66d432e9b45bae7881ffcdb12cd8fd0bf254ef02","https://git.kernel.org/stable/c/7d568fede8eac91161a60b710aa920abe9b0fb9f","https://git.kernel.org/stable/c/bad65b4b0a96139f023eadc28a33125963208449","https://git.kernel.org/stable/c/a2639a7f0f5bf7d73f337f8f077c19415c62ed2c"],"weaknesses":["CWE-362"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/43xxx/CVE-2026-43019.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43019","state":"PUBLISHED","datePublished":"2026-05-01T14:15:23.035Z","dateUpdated":"2026-10-19T19:06:09.770Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-01T14:12:55.975Z"},"containers":{"cna":{"title":"Bluetooth: hci_conn: fix potential UAF in set_cig_params_sync","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_conn: fix potential UAF in set_cig_params_sync\n\nhci_conn lookup and field access must be covered by hdev lock in\nset_cig_params_sync, otherwise it's possible it is freed concurrently.\n\nTake hdev lock to prevent hci_conn from being deleted or modified\nconcurrently.  Just RCU lock is not suitable here, as we also want to\navoid \"tearing\" in the configuration."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"a091289218202bc09d9b9caa8afcde1018584aec","status":"affected","lessThan":"7502c1cf303b69f71d085f5ff7251b0e1b0f09df","versionType":"git"},{"version":"a091289218202bc09d9b9caa8afcde1018584aec","status":"affected","lessThan":"66d432e9b45bae7881ffcdb12cd8fd0bf254ef02","versionType":"git"},{"version":"a091289218202bc09d9b9caa8afcde1018584aec","status":"affected","lessThan":"7d568fede8eac91161a60b710aa920abe9b0fb9f","versionType":"git"},{"version":"a091289218202bc09d9b9caa8afcde1018584aec","status":"affected","lessThan":"bad65b4b0a96139f023eadc28a33125963208449","versionType":"git"},{"version":"a091289218202bc09d9b9caa8afcde1018584aec","status":"affected","lessThan":"a2639a7f0f5bf7d73f337f8f077c19415c62ed2c","versionType":"git"},{"version":"3a273cd0f47dd672d37736e623849374f9ab9ce9","status":"affected","versionType":"git"},{"version":"d8570c4c3f2a3e51b3c8b5e6ec898364c5c03062","status":"affected","versionType":"git"},{"version":"6.4.16","status":"affected","lessThan":"6.5","versionType":"semver"},{"version":"6.5.3","status":"affected","lessThan":"6.6","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":"6.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.6","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.81","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.22","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.12","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","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/7502c1cf303b69f71d085f5ff7251b0e1b0f09df"},{"url":"https://git.kernel.org/stable/c/66d432e9b45bae7881ffcdb12cd8fd0bf254ef02"},{"url":"https://git.kernel.org/stable/c/7d568fede8eac91161a60b710aa920abe9b0fb9f"},{"url":"https://git.kernel.org/stable/c/bad65b4b0a96139f023eadc28a33125963208449"},{"url":"https://git.kernel.org/stable/c/a2639a7f0f5bf7d73f337f8f077c19415c62ed2c"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable `set_cig_params_sync` path is reached through local AF_BLUETOOTH ISO socket operations such as creating a `BTPROTO_ISO` socket, setting ISO QoS/deferred setup, and calling `connect()` or deferred `recvmsg()`. A Bluetooth peer may be involved in normal CIS use, but the vulnerable queueing and racing can be driven by local socket syscalls.\nAC:L - The bug is a race/use-after-free, but the attacker can control the relevant operations by repeatedly creating/binding/connecting and closing ISO sockets while the HCI command work item runs asynchronously. The fix adds `hci_dev_lock`, indicating normal locking, not rare external state, is the missing condition.\nPR:L - AF_BLUETOOTH ISO socket creation and the relevant `BT_ISO_QOS`, `BT_DEFER_SETUP`, and `connect()` path do not require CAP_NET_ADMIN or another privileged check in the inspected path. The attacker needs local code execution as an unprivileged user on a system with a running Bluetooth ISO-capable controller.\nUI:N - No victim action is required once the local attacker can execute socket syscalls. The attacker can create, configure, connect, and close the sockets directly.\nS:U - The vulnerability corrupts or reuses memory within the kernel Bluetooth/HCI connection management context. Exploitation would be kernel compromise or denial of service within the same security authority, not a boundary crossing such as guest-to-host escape.\nC:H - This is a use-after-free of `struct hci_conn`, with freed object fields read after lookup without holding the device lock. Per kernel UAF scoring guidance and plausible heap reuse, this can support high confidentiality impact.\nI:H - The stale `hci_conn` contents are used to build HCI command parameters, and UAF conditions in kernel heap objects are generally exploitable with heap grooming for control/data corruption. Following the required higher-severity rule for UAFs, integrity impact is High.\nA:H - A stale `hci_conn` dereference in asynchronous HCI command work can trigger kernel memory safety failures, including KASAN-detected slab-use-after-free, oops, or panic. Repeated local triggering makes denial of service high impact."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:25:18.558Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"6.6.143"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"6.12.81"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"6.18.22"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"6.19.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"7.0"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.4.16"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-43019","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:13:33.625290Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-362","lang":"en","type":"CWE","description":"CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:06:09.770Z"}}]}}}