{"id":"CVE-2026-15460","aliases":["EUVD-2026-75212","GHSA-hx89-rm6c-hjrh"],"status":"published","title":"Missing channel-state validation in Zephyr Bluetooth Classic L2CAP receive path","description":"The Bluetooth Classic (BR/EDR) L2CAP receive handler bt_l2cap_br_recv() in subsys/bluetooth/host/classic/l2cap_br.c dispatched inbound data PDUs based only on the destination channel ID, without checking that the target channel had reached the BT_L2CAP_CONNECTED state. A dynamic channel is assigned its RX CID and added to the connection's channel list while still in BT_L2CAP_CONNECTING (and later BT_L2CAP_CONFIG) — before configuration completes and, for PSMs that require security, before the peer is authenticated (l2cap_br_conn_req()).\n\nBecause the channel is already findable by bt_l2cap_br_lookup_rx_cid() during this window, a remote peer within radio range can send a data PDU addressed to that CID and have it processed on a not-yet-established channel. The dispatch keys off channel fields (BR_CHAN(chan)-\u003erx.mode, rx.mps) that are only initialized during configuration by l2cap_br_conf(); since channel objects are pooled and bt_l2cap_br_chan_del() does not reset rx.mode or the reassembly buffer _sdu, a reused channel can carry stale state into the CONNECTING window and route the frame into the retransmission/flow-control path (bt_l2cap_br_ret_fc_recv()) with stale parameters and a possibly stale _sdu pointer.\n\nThe impact is delivery of attacker data to upper-layer protocol handlers on a half-open (and possibly unauthenticated) channel, plus operation on stale or partially initialized channel state on reused channel objects — leading to channel/link teardown (denial of service) and, in the stale-_sdu case, a dangling-pointer condition. The fix adds an explicit BR_CHAN(chan)-\u003estate \u003c BT_L2CAP_CONNECTED guard that drops any data received before the channel is fully connected.","severity":{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00249,"percentile":0.16333,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-666"],"published":"2026-09-09T22:40:46Z","modified":"2026-11-04T05:00:08Z","products":[{"vendor":"zephyrproject","product":"zephyr"},{"vendor":"zephyrproject-rtos","product":"zephyr"}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/2738ee921ba61ba2e644c95bceba302896dd8c19","tags":["patch","fix"]},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-hx89-rm6c-hjrh","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/15xxx/CVE-2026-15460.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-15460","tags":["advisory"]},{"url":"https://github.com/zephyrproject-rtos/zephyr","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-15460","title":"Missing channel-state validation in Zephyr Bluetooth Classic L2CAP receive path","description":"The Bluetooth Classic (BR/EDR) L2CAP receive handler bt_l2cap_br_recv() in subsys/bluetooth/host/classic/l2cap_br.c dispatched inbound data PDUs based only on the destination channel ID, without checking that the target channel had reached the BT_L2CAP_CONNECTED state. A dynamic channel is assigned its RX CID and added to the connection's channel list while still in BT_L2CAP_CONNECTING (and later BT_L2CAP_CONFIG) — before configuration completes and, for PSMs that require security, before the peer is authenticated (l2cap_br_conn_req()).\n\nBecause the channel is already findable by bt_l2cap_br_lookup_rx_cid() during this window, a remote peer within radio range can send a data PDU addressed to that CID and have it processed on a not-yet-established channel. The dispatch keys off channel fields (BR_CHAN(chan)-\u003erx.mode, rx.mps) that are only initialized during configuration by l2cap_br_conf(); since channel objects are pooled and bt_l2cap_br_chan_del() does not reset rx.mode or the reassembly buffer _sdu, a reused channel can carry stale state into the CONNECTING window and route the frame into the retransmission/flow-control path (bt_l2cap_br_ret_fc_recv()) with stale parameters and a possibly stale _sdu pointer.\n\nThe impact is delivery of attacker data to upper-layer protocol handlers on a half-open (and possibly unauthenticated) channel, plus operation on stale or partially initialized channel state on reused channel objects — leading to channel/link teardown (denial of service) and, in the stale-_sdu case, a dangling-pointer condition. The fix adds an explicit BR_CHAN(chan)-\u003estate \u003c BT_L2CAP_CONNECTED guard that drops any data received before the channel is fully connected.","status":"published","published":"2026-09-09T22:40:46.492Z","modified":"2026-11-04T05:00:08.211Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-666"],"updated_at":"2026-11-04T05:21:48.223566Z"}],"euvd":[{"id":"EUVD-2026-75212","description":"The Bluetooth Classic (BR/EDR) L2CAP receive handler bt_l2cap_br_recv() in subsys/bluetooth/host/classic/l2cap_br.c dispatched inbound data PDUs based only on the destination channel ID, without checking that the target channel had reached the BT_L2CAP_CONNECTED state. A dynamic channel is assigned its RX CID and added to the connection's channel list while still in BT_L2CAP_CONNECTING (and later BT_L2CAP_CONFIG) — before configuration completes and, for PSMs that require security, before the peer is authenticated (l2cap_br_conn_req()).\n\nBecause the channel is already findable by bt_l2cap_br_lookup_rx_cid() during this window, a remote peer within radio range can send a data PDU addressed to that CID and have it processed on a not-yet-established channel. The dispatch keys off channel fields (BR_CHAN(chan)-\u003erx.mode, rx.mps) that are only initialized during configuration by l2cap_br_conf(); since channel objects are pooled and bt_l2cap_br_chan_del() does not reset rx.mode or the reassembly buffer _sdu, a reused channel can carry stale state into the CONNECTING window and route the frame into the retransmission/flow-control path (bt_l2cap_br_ret_fc_recv()) with stale parameters and a possibly stale _sdu pointer.\n\nThe impact is delivery of attacker data to upper-layer protocol handlers on a half-open (and possibly unauthenticated) channel, plus operation on stale or partially initialized channel state on reused channel objects — leading to channel/link teardown (denial of service) and, in the stale-_sdu case, a dangling-pointer condition. The fix adds an explicit BR_CHAN(chan)-\u003estate \u003c BT_L2CAP_CONNECTED guard that drops any data received before the channel is fully connected.","status":"published","published":"2026-09-09T22:40:46Z","modified":"2026-11-04T05:00:08Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium"}],"updated_at":"2026-11-04T07:00:56.720215Z"}],"nvd":[{"id":"CVE-2026-15460","description":"The Bluetooth Classic (BR/EDR) L2CAP receive handler bt_l2cap_br_recv() in subsys/bluetooth/host/classic/l2cap_br.c dispatched inbound data PDUs based only on the destination channel ID, without checking that the target channel had reached the BT_L2CAP_CONNECTED state. A dynamic channel is assigned its RX CID and added to the connection's channel list while still in BT_L2CAP_CONNECTING (and later BT_L2CAP_CONFIG) — before configuration completes and, for PSMs that require security, before the peer is authenticated (l2cap_br_conn_req()).\n\nBecause the channel is already findable by bt_l2cap_br_lookup_rx_cid() during this window, a remote peer within radio range can send a data PDU addressed to that CID and have it processed on a not-yet-established channel. The dispatch keys off channel fields (BR_CHAN(chan)-\u003erx.mode, rx.mps) that are only initialized during configuration by l2cap_br_conf(); since channel objects are pooled and bt_l2cap_br_chan_del() does not reset rx.mode or the reassembly buffer _sdu, a reused channel can carry stale state into the CONNECTING window and route the frame into the retransmission/flow-control path (bt_l2cap_br_ret_fc_recv()) with stale parameters and a possibly stale _sdu pointer.\n\nThe impact is delivery of attacker data to upper-layer protocol handlers on a half-open (and possibly unauthenticated) channel, plus operation on stale or partially initialized channel state on reused channel objects — leading to channel/link teardown (denial of service) and, in the stale-_sdu case, a dangling-pointer condition. The fix adds an explicit BR_CHAN(chan)-\u003estate \u003c BT_L2CAP_CONNECTED guard that drops any data received before the channel is fully connected.","status":"published","published":"2026-09-09T23:16:54.617Z","modified":"2026-11-04T05:18:43.573Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-666"],"updated_at":"2026-11-04T06:53:20.502063Z"}],"osv":[{"id":"CVE-2026-15460","title":"Missing channel-state validation in Zephyr Bluetooth Classic L2CAP receive path","description":"The Bluetooth Classic (BR/EDR) L2CAP receive handler bt_l2cap_br_recv() in subsys/bluetooth/host/classic/l2cap_br.c dispatched inbound data PDUs based only on the destination channel ID, without checking that the target channel had reached the BT_L2CAP_CONNECTED state. A dynamic channel is assigned its RX CID and added to the connection's channel list while still in BT_L2CAP_CONNECTING (and later BT_L2CAP_CONFIG) — before configuration completes and, for PSMs that require security, before the peer is authenticated (l2cap_br_conn_req()).\n\nBecause the channel is already findable by bt_l2cap_br_lookup_rx_cid() during this window, a remote peer within radio range can send a data PDU addressed to that CID and have it processed on a not-yet-established channel. The dispatch keys off channel fields (BR_CHAN(chan)-\u003erx.mode, rx.mps) that are only initialized during configuration by l2cap_br_conf(); since channel objects are pooled and bt_l2cap_br_chan_del() does not reset rx.mode or the reassembly buffer _sdu, a reused channel can carry stale state into the CONNECTING window and route the frame into the retransmission/flow-control path (bt_l2cap_br_ret_fc_recv()) with stale parameters and a possibly stale _sdu pointer.\n\nThe impact is delivery of attacker data to upper-layer protocol handlers on a half-open (and possibly unauthenticated) channel, plus operation on stale or partially initialized channel state on reused channel objects — leading to channel/link teardown (denial of service) and, in the stale-_sdu case, a dangling-pointer condition. The fix adds an explicit BR_CHAN(chan)-\u003estate \u003c BT_L2CAP_CONNECTED guard that drops any data received before the channel is fully connected.","status":"published","published":"2026-09-09T22:40:46.492Z","modified":"2026-11-05T03:31:26.181589697Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium"}],"cwes":["CWE-666"],"updated_at":"2026-11-05T07:12:28.867005Z"}]}}