{"id":"CVE-2026-53276","state":"PUBLISHED","title":"Bluetooth: ISO: Fix a use-after-free of the hci_conn pointer","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: ISO: Fix a use-after-free of the hci_conn pointer\n\nIn iso_sock_rebind_bc(), the bis pointer is cached, then the socket lock is\ndropped:\n\tbis = iso_pi(sk)->conn->hcon;\n\t/* Release the socket before lookups since that requires hci_dev_lock\n\t * which shall not be acquired while holding sock_lock for proper\n\t * ordering.\n\t */\n\trelease_sock(sk);\n\thci_dev_lock(bis->hdev);\n\nDuring the unlocked window, could a concurrent close() destroy the connection\nand free the bis structure, causing hci_dev_lock(bis->hdev) to access memory\nafter it is freed, fix this by using the hdev reference which was safely\nacquired via iso_conn_get_hdev().","publishedAt":"2026-06-25T08:39:59.804Z","updatedAt":"2026-08-05T12:34:52.648Z","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":"d3413703d5f8b7d1e6f514f9440ed5da1bc30796","status":"affected","lessThan":"d324b8aa20bd3c3394e3647dc22491d88f3f4e7a","versionType":"git"},{"version":"d3413703d5f8b7d1e6f514f9440ed5da1bc30796","status":"affected","lessThan":"f50331f2a1441ec49988832c3a95f2edacc47322","versionType":"git"}],"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":"6.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.19","versionType":"semver"},{"version":"7.0.13","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","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/d324b8aa20bd3c3394e3647dc22491d88f3f4e7a","https://git.kernel.org/stable/c/f50331f2a1441ec49988832c3a95f2edacc47322"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53276.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53276","state":"PUBLISHED","datePublished":"2026-06-25T08:39:59.804Z","dateUpdated":"2026-08-05T12:34:52.648Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.395Z"},"containers":{"cna":{"title":"Bluetooth: ISO: Fix a use-after-free of the hci_conn pointer","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: ISO: Fix a use-after-free of the hci_conn pointer\n\nIn iso_sock_rebind_bc(), the bis pointer is cached, then the socket lock is\ndropped:\n\tbis = iso_pi(sk)->conn->hcon;\n\t/* Release the socket before lookups since that requires hci_dev_lock\n\t * which shall not be acquired while holding sock_lock for proper\n\t * ordering.\n\t */\n\trelease_sock(sk);\n\thci_dev_lock(bis->hdev);\n\nDuring the unlocked window, could a concurrent close() destroy the connection\nand free the bis structure, causing hci_dev_lock(bis->hdev) to access memory\nafter it is freed, fix this by using the hdev reference which was safely\nacquired via iso_conn_get_hdev()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d3413703d5f8b7d1e6f514f9440ed5da1bc30796","status":"affected","lessThan":"d324b8aa20bd3c3394e3647dc22491d88f3f4e7a","versionType":"git"},{"version":"d3413703d5f8b7d1e6f514f9440ed5da1bc30796","status":"affected","lessThan":"f50331f2a1441ec49988832c3a95f2edacc47322","versionType":"git"}],"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":"6.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.19","versionType":"semver"},{"version":"7.0.13","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","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/d324b8aa20bd3c3394e3647dc22491d88f3f4e7a"},{"url":"https://git.kernel.org/stable/c/f50331f2a1441ec49988832c3a95f2edacc47322"}],"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 path is reached through local AF_BLUETOOTH ISO socket operations, specifically bind() rebinding on an already connected or CONNECT2 ISO socket. An adjacent Bluetooth peer may be involved in establishing BIS/PAST state, but the actual trigger is a local syscall/race, not an unauthenticated received packet alone.\nAC:L - The bug is a use-after-free race where the rebind path drops the socket lock and a concurrent close can free the cached hci_conn pointer. A local attacker can control both sides by using concurrent operations on their own socket, so no uncontrollable condition is required.\nPR:L - The ISO socket create/bind/connect/rebind path has no CAP_NET_ADMIN or CAP_NET_RAW check, but it requires the attacker to run local code and create/use a Bluetooth ISO socket. This is therefore basic unprivileged local access rather than real administrative privilege.\nUI:N - No victim user action is required once the attacker can run local code; the attacker can create the socket state and trigger the concurrent bind/close race themselves.\nS:U - The vulnerable code is in the kernel Bluetooth stack and impacts the same kernel security authority. There is no VM escape, IOMMU bypass, or other cross-scope boundary indicated.\nC:H - This is a use-after-free of an hci_conn pointer, and under the required higher-severity rule UAFs are treated as capable of enabling memory disclosure through heap reuse and object manipulation.\nI:H - A kernel use-after-free can potentially be shaped into control-flow or data-structure corruption via heap spraying/reuse. Under the required higher-severity rule, this supports high integrity impact.\nA:H - The stale hci_conn dereference can access freed memory while taking hci_dev_lock(bis->hdev), which can oops or panic the kernel. A repeatable local trigger gives high availability impact."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:34:52.648Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"7.0.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}