{"attribution":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","cve":{"id":"CVE-2026-90832","sourceIdentifier":"vulnerabilities@zephyrproject.org","published":"2026-11-10T22:21:14.167","lastModified":"2026-11-10T22:21:14.280","vulnStatus":"Awaiting Analysis","cveTags":[],"descriptions":[{"lang":"en","value":"bt_hci_le_per_adv_report_common() in subsys/bluetooth/host/scan.c handles the HCI_LE_Periodic_Advertising_Report (and _v2) event. It verified that the fixed event header was present and that the controller-declared Data_Length fits the tailroom of the periodic-sync reassembly buffer, but never checked that the event actually carried as many data bytes as evt-\u003elength claims. Both reassembly paths — DATA_STATUS_PARTIAL, and DATA_STATUS_COMPLETE while a chain is already in progress — then called net_buf_simple_add_mem(\u0026per_adv_sync-\u003ereassembly, buf-\u003edata, evt-\u003elength), copying up to 255 bytes starting past the end of the event's real payload.\n\nThe Data_Length field originates in the HCI controller, so the flaw is reachable in host-only/split builds where the controller is a separate part reached over H4 UART, SPI, USB or an inter-core IPC transport: a malicious, compromised or buggy controller (or an attacker able to inject on that link) can send a report declaring a length larger than the event payload. The generic event dispatcher in subsys/bluetooth/host/hci_core.c only enforces a per-event minimum length and never cross-checks the subevent's internal length field, so nothing else catches it. Builds using Zephyr's own in-image controller are not affected, because the controller always emits a length matching the bytes it appends.\n\nExploitation additionally requires CONFIG_BT_PER_ADV_SYNC with CONFIG_BT_PER_ADV_SYNC_BUF_SIZE \u003e 0 (the option defaults to 0, which compiles the reassembly block out; LE Audio broadcast-sink and Public Broadcast Profile applications that reassemble fragmented periodic advertising data set it), and an established periodic advertising sync.\n\nThe consequence is an out-of-bounds read of adjacent HCI RX-pool memory — including stale contents of previously received HCI events — which is copied into the reassembly buffer and then delivered to every registered bt_le_per_adv_sync_cb.recv listener as if it were received advertising data, so the disclosed memory becomes application-visible and may be forwarded off-device. The write side remains in bounds because the tailroom check uses the same length value, so there is no memory corruption; impact is limited to information disclosure and undefined behaviour on the over-read. The fix drops any report whose declared length exceeds the remaining event payload, matching the guard already present in the extended and legacy advertising report handlers."}],"affected":[{"source":"vulnerabilities@zephyrproject.org","affectedData":[{"vendor":"zephyrproject","product":"zephyr","defaultStatus":"unaffected","collectionURL":"https://github.com/zephyrproject-rtos/zephyr","packageName":"zephyr","programFiles":["subsys/bluetooth/host/scan.c"],"programRoutines":[{"name":"bt_hci_le_per_adv_report"},{"name":"bt_hci_le_per_adv_report_common"}],"versions":[{"version":"3.0.0","lessThan":"4.3.2","versionType":"semver","status":"affected"},{"version":"4.4.0","lessThan":"4.5.0","versionType":"semver","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"vulnerabilities@zephyrproject.org","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","baseScore":4.3,"baseSeverity":"MEDIUM","attackVector":"ADJACENT_NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"NONE","availabilityImpact":"NONE"},"exploitabilityScore":2.8,"impactScore":1.4}]},"weaknesses":[{"source":"vulnerabilities@zephyrproject.org","type":"Secondary","description":[{"lang":"en","value":"CWE-125"}]}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/e9c3252c244b094b9caf6f426ffb77c509e58a9f","source":"vulnerabilities@zephyrproject.org"},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-2q4q-gv2c-997j","source":"vulnerabilities@zephyrproject.org"}]}}