{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-11368","assignerOrgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","state":"PUBLISHED","assignerShortName":"zephyr","dateReserved":"2026-06-05T12:00:57.310Z","datePublished":"2026-08-04T14:23:28.866Z","dateUpdated":"2026-08-04T17:57:40.823Z"},"containers":{"cna":{"providerMetadata":{"orgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","shortName":"zephyr","dateUpdated":"2026-08-04T14:23:28.866Z"},"title":"Use-after-free in Bluetooth host ATT TX completion on disconnect mid-transfer","descriptions":[{"lang":"en","value":"The Bluetooth host ATT layer (subsys/bluetooth/host/att.c) associates each in-flight ATT TX buffer with its owning channel via the static tx_meta_data_storage[] array (data->att_chan = chan). When a buffer's last reference is dropped, its net-buf destroy callback defers the completion handling to the system workqueue (att_tx_destroy -> att_tx_destroy_work_handler -> att_on_sent_cb -> bt_att_sent), where bt_att_sent dereferences the channel and its ATT context (sys_slist_get(&att->reqs)).\n\nWhen a peer disconnects while an ATT PDU (a server notification/indication or any response) is still in flight in the controller TX path, L2CAP tears the channel down in l2cap_chan_del(): it runs the disconnected callback and then the released callback (bt_att_released), which frees the channel slab slot. Because the in-flight buffer is held by the connection TX path rather than the channel's own queue, its deferred destroy work can run after the channel has been freed. The att_on_sent_cb guard intended to drop the stale callback itself dereferences meta->att_chan, which is now a dangling pointer into a freed (and possibly reused) slab slot.\n\nA remote peer with an ATT connection can drive this by disconnecting during routine ATT traffic; no pairing or user interaction is required to reach the ATT bearer. The result is a use-after-free read/write of freed channel memory, reliably crashing the Bluetooth host (denial of service) and, because the channel slab slot may be reused, potentially corrupting live memory.\n\nThe fix makes bt_att_released() NULL the att_chan field of every tx_meta_data_storage[] entry still referencing the channel before freeing it, so the deferred guard observes a NULL pointer and drops the callback. Teardown and the destroy work both run on the cooperative system workqueue, so the array update is serialized and needs no lock."}],"affected":[{"vendor":"zephyrproject","product":"zephyr","collectionURL":"https://github.com/zephyrproject-rtos/zephyr","packageName":"zephyr","defaultStatus":"unaffected","programFiles":["subsys/bluetooth/host/att.c"],"versions":[{"version":"4.4.0","status":"affected","lessThan":"4.5.0","versionType":"semver"}]}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/dfdea9bad8d9b5b31c125e97fcffb549f2217caa","name":"Fix commit","tags":["patch"]},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-85vg-gwc4-77g7","name":"GHSA-85vg-gwc4-77g7"}],"metrics":[{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","baseScore":7.1,"baseSeverity":"HIGH"}}],"problemTypes":[{"descriptions":[{"lang":"en","description":"use-after-free","cweId":"CWE-416","type":"CWE"}]}],"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-04T17:56:36.608577Z","id":"CVE-2026-11368","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-08-04T17:57:40.823Z"}}]}}