Live › vulnerability › CVE-2026-82389
Go to dashboardA remote Bluetooth Classic device can advertise an out-of-range RFCOMM channel that makes the Hands-Free Audio Gateway free its SDP request state while still linked, leaving dangling pointers. The result is a crash or hang of the Bluetooth stack, with no attacker-controlled write.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-26 17:31 UTC. All times on this page are UTC.
Only Zephyr builds with both CONFIG_BT_CLASSIC and CONFIG_BT_HFP_AG enabled that run the Audio Gateway role are exposed. Builds without the Audio Gateway role, or without Bluetooth Classic, can skip it.
No product ranges from the sources yet.
CONFIG_BT_CLASSIC=y and CONFIG_BT_HFP_AG=y.CONFIG_BT_HFP_AG if the Audio Gateway role is not needed.Each row is the first time that source carried this signal. The analyst’s rows are its own findings.
In the Bluetooth Classic Hands-Free Profile Audio Gateway role, hfp_ag_create() in subsys/bluetooth/host/classic/hfp_ag.c starts an SDP discovery toward the peer, which links the embedded ag->sdp_param._node into the SDP client's pending request list in subsys/bluetooth/host/classic/sdp.c. If the subsequent bt_rfcomm_dlc_connect() call fails, bt_hfp_ag_connect() cleaned up by memset()-ing the entire AG object while that node was still linked, and while ag->slc_work could still be queued on the system work queue. An in-flight SDP discovery cannot be cancelled — bt_sdp_discover_cancel() is declared in the public header but has no implementation — so the request stays in the list with its func, pool and uuid pointers zeroed.
The RFCOMM channel passed to bt_hfp_ag_connect() is taken from the peer's own SDP Hands-Free service record in the normal AG flow (bt_sdp_get_proto_param() performs no range validation, and samples/bluetooth/classic/handsfree_ag feeds the value straight through), so a remote BR/EDR device in radio range that advertises an RFCOMM channel outside the valid range 0x01..0x1e deterministically forces bt_rfcomm_dlc_connect() to fail and reach the wipe. Reading the peer's SDP record requires no pairing, and the peer can also trigger the failure by dropping the ACL or racing an RFCOMM DLC on the same DLCI at the right moment.
When the SDP client next advances its request list, sdp_client_discover() dereferences the zeroed parameters — net_buf_alloc(param->pool, …) with a NULL pool and param->uuid->type — and the result-notification paths call through the NULL params->func. Zeroing a linked node also truncates the request list behind a stale tail pointer, and re-arming the freed AG slot re-appends the same node and can produce a self-looping list that hangs the Bluetooth RX thread. The impact is a crash or hang of the Bluetooth stack; the written value is a constant zero at a fixed static address, so no attacker-controlled write is available.
Only builds with CONFIG_BT_CLASSIC and CONFIG_BT_HFP_AG that use the Audio Gateway role are affected.
This page as .md · .json · in your agent: get_signal("CVE-2026-82389")
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