{"id":"CVE-2026-98461","kind":"vulnerability","aliases":["CVE-2026-98461"],"related":[],"title":"Linux kernel: Bluetooth socket filter reads past short HCI events","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sock: validate event length before filtering\n\nis_filtered_packet() reads the event code from skb->data[0] without first\nchecking that the skb is nonempty. When an opcode filter is configured,\nit also reads the command opcode at offsets 3 or 4 without checking that\na Command Complete or Command Status event is long enough.\n\nhci_send_to_sock() invokes the filter before hci_event_packet() validates\nthe event header. A malformed event supplied by a controller or a vhci\ndevice can therefore cause an out-of-bounds read.\n\nKeep the unmasked event code for the opcode checks. The masked value is\nneeded for the 64-bit event bitmap, but using it to identify command events\naliases event codes above 0x3f. In particular, Synchronous Train Complete\n(0x4f) was treated as Command Status (0x0f) even though its payload has no\nopcode.\n\nReject actual command events that are too short for the field being\ninspected. A truncated command event cannot match a configured opcode.","summary":"The Linux kernel Bluetooth HCI socket filter reads event bytes before checking the packet length, so a malformed event from a controller or vhci device can cause an out-of-bounds read. The sources describe a read of memory outside the packet; they do not state a confirmed code execution or data leak.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["bluetooth","infrastructure","linux-kernel","self-hosted"],"not_affected_if":["no-bluetooth-hardware"],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-10-18T16:16:56+00:00","first_seen_at":"2026-10-23T21:57:15+00:00","triaged_at":"2026-10-25T05:27:14+00:00","updated_at":"2026-10-25T05:27:14+00:00","category":"infrastructure","confidence":0.5,"triage":{"at":"2026-10-25T05:27:14Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"local","title":"Linux kernel: Bluetooth socket filter reads past short HCI events","impact":"low","summary":"The Linux kernel Bluetooth HCI socket filter reads event bytes before checking the packet length, so a malformed event from a controller or vhci device can cause an out-of-bounds read. The sources describe a read of memory outside the packet; they do not state a confirmed code execution or data leak.","category":"infrastructure","nicknames":[],"who_cares":["linux-kernel","bluetooth","self-hosted"],"confidence":0.5,"needs_auth":"unknown","worst_case":"out-of-bounds kernel memory read from malformed Bluetooth event","analyst_note":"Check the upstream kernel fix commit and stable branch versions for the Bluetooth hci_sock fix via the NVD link, and confirm whether the read is reachable without a local Bluetooth device.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["no-bluetooth-hardware"],"who_is_affected":"Systems running a Linux kernel with Bluetooth HCI socket support and a configured HCI opcode filter, where a malformed event can reach the host from a Bluetooth controller or a vhci device. The sources do not list fixed kernel versions. Systems without Bluetooth hardware or without the HCI socket in use are likely unaffected, but the sources do not say this explicitly.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"low"},"cost_usd":0.000621,"input_tokens":3563,"output_tokens":530,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':12A,15A '-98461':13A,16A '0':107C '0x0f':224C '0x3f':212C '0x4f':218C '3':130C '4':132C '64':197C 'actual':233C 'alias':208C 'also':123C 'bit':198C 'bitmap':200C 'bluetooth':3A,17B,28B,89C 'bound':56B,179C 'byte':34B 'cannot':249C 'caus':51B,174C 'check':36B,110C,134C,189C 'code':74B,103C,185C,210C 'command':126C,137C,140C,206C,222C,234C,247C 'complet':138C,217C 'configur':121C,252C 'confirm':73B 'control':46B,167C 'cve':11A,14A 'data':77B,106C 'describ':60B 'devic':49B,171C 'enough':145C 'even':225C 'event':10A,33B,43B,93C,102C,142C,155C,159C,163C,184C,199C,207C,209C,235C,248C 'execut':75B 'field':242C 'filter':5A,31B,96C,98C,119C,152C 'first':109C 'follow':84C 'hci':9A,29B,90C,146C,154C 'header':160C 'host':24B 'identifi':205C 'infrastructur':18B 'inspect':244C 'invok':150C 'keep':181C 'kernel':2A,21B,27B,82C 'leak':78B 'length':39B,94C 'linux':1A,20B,26B,81C 'linux-kernel':19B 'long':144C 'malform':42B,162C 'mask':191C 'match':250C 'memori':64B 'need':194C 'nonempti':115C 'offset':129C 'opcod':118C,127C,188C,231C,253C 'out-of-bound':53B,176C 'outsid':65B 'packet':38B,67B,99C,156C 'particular':214C 'past':7A 'payload':228C 'read':6A,32B,57B,62B,100C,124C,180C 'reject':232C 'resolv':88C 'self':23B 'self-host':22B 'send':147C 'short':8A,239C 'skb':105C,113C 'sock':91C,149C 'socket':4A,30B 'sourc':59B 'state':71B 'status':141C,223C 'suppli':164C 'synchron':215C 'therefor':173C 'though':226C 'train':216C 'treat':220C 'truncat':246C 'unmask':183C 'use':202C 'valid':92C,157C 'valu':192C 'vhci':48B,170C 'vulner':85C 'without':108C,133C","nicknames":[],"mitigations":[],"who_affected":"Systems running a Linux kernel with Bluetooth HCI socket support and a configured HCI opcode filter, where a malformed event can reach the host from a Bluetooth controller or a vhci device. The sources do not list fixed kernel versions. Systems without Bluetooth hardware or without the HCI socket in use are likely unaffected, but the sources do not say this explicitly.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-18T16:16:56+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-98461","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98461","severity":null,"published_at":"2026-10-18T16:16:56+00:00","modified_at":"2026-10-19T10:18:55+00:00","first_seen_at":"2026-10-23T21:57:15+00:00","fetched_at":"2026-10-23T22:28:56+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}