CVE-2026-11894

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-11894", "assignerOrgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "state": "PUBLISHED", "assignerShortName": "zephyr", "dateReserved": "2026-06-10T15:25:18.616Z", "datePublished": "2026-08-11T05:08:51.464Z", "dateUpdated": "2026-08-11T17:04:49.434Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "shortName": "zephyr", "dateUpdated": "2026-08-11T05:08:51.464Z"}, "title": "Double-free / use-after-free in Realtek BEE Bluetooth HCI driver `send()` error paths", "descriptions": [{"lang": "en", "value": "The Realtek BEE Bluetooth HCI driver's send callback, bt_hci_bee_send() in drivers/bluetooth/hci/hci_bee.c, violated the bt_hci_driver_api buffer-ownership contract. That contract requires the driver to consume (unref) the transmit net_buf only on success; on an error return the host caller retains ownership and unrefs the buffer itself. The pre-fix code routed all error paths through a shared cleanup label that unconditionally called net_buf_unref(buf) before returning the error code.\n\nBecause the host TX paths (in subsys/bluetooth/host/hci_core.c) unref the buffer again after send() returns an error, the buffer is freed twice: the driver returns it to its net_buf pool and the host then unrefs the already-freed buffer, corrupting the shared pool / underflowing the reference count (CWE-415). The same error branch additionally dereferenced buf->len inside a LOG_ERR call after the buffer had already been unref'd, a read of freed memory (CWE-416) that is compiled in at the default error log level.\n\nThe failing edges are reached when the controller's host-to-controller buffer allocation fails or the controller send fails (resource-exhaustion / IO conditions). A remote Bluetooth peer can push the device toward these conditions indirectly by driving heavy host transmit activity, at which point the double-free corrupts the host net_buf pool and most likely crashes the device, with residual potential for further memory corruption. The impact is confined to builds using this specific Realtek BEE HCI driver.\n\nThe fix returns early from each error path without unreffing and unrefs the buffer only on the success path, restoring the ownership contract and eliminating both the double-free and the use-after-free read."}], "affected": [{"vendor": "zephyrproject", "product": "zephyr", "collectionURL": "https://github.com/zephyrproject-rtos/zephyr", "packageName": "zephyr", "defaultStatus": "unaffected", "programFiles": ["drivers/bluetooth/hci/hci_bee.c"], "versions": [{"version": "4.4.0", "status": "affected", "versionType": "semver", "lessThan": "4.4.2"}]}], "references": [{"url": "https://github.com/zephyrproject-rtos/zephyr/commit/9a684b5c314fb1d8670b01f7b6c4450a9353906c", "name": "Fix commit", "tags": ["patch"]}, {"url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-v9mj-h2m6-v9c6", "name": "GHSA-v9mj-h2m6-v9c6"}], "metrics": [{"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H", "baseScore": 5.9, "baseSeverity": "MEDIUM"}}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "use-after-free", "cweId": "CWE-415", "type": "CWE"}]}], "x_generator": {"engine": "cvelib 1.8.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-08-11T17:04:26.697150Z", "id": "CVE-2026-11894", "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": "2026-08-11T17:04:49.434Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-11894", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-11T17:04:26.697150Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-11T17:04:42.489Z"}}], "cna": {"title": "Double-free / use-after-free in Realtek BEE Bluetooth HCI driver `send()` error paths", "metrics": [{"format": "CVSS", "cvssV3_1": {"version": "3.1", "baseScore": 5.9, "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H"}}], "affected": [{"vendor": "zephyrproject", "product": "zephyr", "versions": [{"status": "affected", "version": "4.4.0", "lessThan": "4.4.2", "versionType": "semver"}], "packageName": "zephyr", "programFiles": ["drivers/bluetooth/hci/hci_bee.c"], "collectionURL": "https://github.com/zephyrproject-rtos/zephyr", "defaultStatus": "unaffected"}], "references": [{"url": "https://github.com/zephyrproject-rtos/zephyr/commit/9a684b5c314fb1d8670b01f7b6c4450a9353906c", "name": "Fix commit", "tags": ["patch"]}, {"url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-v9mj-h2m6-v9c6", "name": "GHSA-v9mj-h2m6-v9c6"}], "x_generator": {"engine": "cvelib 1.8.0"}, "descriptions": [{"lang": "en", "value": "The Realtek BEE Bluetooth HCI driver's send callback, bt_hci_bee_send() in drivers/bluetooth/hci/hci_bee.c, violated the bt_hci_driver_api buffer-ownership contract. That contract requires the driver to consume (unref) the transmit net_buf only on success; on an error return the host caller retains ownership and unrefs the buffer itself. The pre-fix code routed all error paths through a shared cleanup label that unconditionally called net_buf_unref(buf) before returning the error code.\n\nBecause the host TX paths (in subsys/bluetooth/host/hci_core.c) unref the buffer again after send() returns an error, the buffer is freed twice: the driver returns it to its net_buf pool and the host then unrefs the already-freed buffer, corrupting the shared pool / underflowing the reference count (CWE-415). The same error branch additionally dereferenced buf->len inside a LOG_ERR call after the buffer had already been unref'd, a read of freed memory (CWE-416) that is compiled in at the default error log level.\n\nThe failing edges are reached when the controller's host-to-controller buffer allocation fails or the controller send fails (resource-exhaustion / IO conditions). A remote Bluetooth peer can push the device toward these conditions indirectly by driving heavy host transmit activity, at which point the double-free corrupts the host net_buf pool and most likely crashes the device, with residual potential for further memory corruption. The impact is confined to builds using this specific Realtek BEE HCI driver.\n\nThe fix returns early from each error path without unreffing and unrefs the buffer only on the success path, restoring the ownership contract and eliminating both the double-free and the use-after-free read."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-415", "description": "use-after-free"}]}], "providerMetadata": {"orgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "shortName": "zephyr", "dateUpdated": "2026-08-11T05:08:51.464Z"}}}, "cveMetadata": {"cveId": "CVE-2026-11894", "state": "PUBLISHED", "dateUpdated": "2026-08-11T17:04:49.434Z", "dateReserved": "2026-06-10T15:25:18.616Z", "assignerOrgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "datePublished": "2026-08-11T05:08:51.464Z", "assignerShortName": "zephyr"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"collectionURL": "https://github.com/zephyrproject-rtos/zephyr", "defaultStatus": "unaffected", "packageName": "zephyr", "product": "zephyr", "programFiles": ["drivers/bluetooth/hci/hci_bee.c"], "vendor": "zephyrproject", "versions": [{"lessThan": "4.4.2", "status": "affected", "version": "4.4.0", "versionType": "semver"}]}], "source": "vulnerabilities@zephyrproject.org"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "The Realtek BEE Bluetooth HCI driver's send callback, bt_hci_bee_send() in drivers/bluetooth/hci/hci_bee.c, violated the bt_hci_driver_api buffer-ownership contract. That contract requires the driver to consume (unref) the transmit net_buf only on success; on an error return the host caller retains ownership and unrefs the buffer itself. The pre-fix code routed all error paths through a shared cleanup label that unconditionally called net_buf_unref(buf) before returning the error code.\n\nBecause the host TX paths (in subsys/bluetooth/host/hci_core.c) unref the buffer again after send() returns an error, the buffer is freed twice: the driver returns it to its net_buf pool and the host then unrefs the already-freed buffer, corrupting the shared pool / underflowing the reference count (CWE-415). The same error branch additionally dereferenced buf->len inside a LOG_ERR call after the buffer had already been unref'd, a read of freed memory (CWE-416) that is compiled in at the default error log level.\n\nThe failing edges are reached when the controller's host-to-controller buffer allocation fails or the controller send fails (resource-exhaustion / IO conditions). A remote Bluetooth peer can push the device toward these conditions indirectly by driving heavy host transmit activity, at which point the double-free corrupts the host net_buf pool and most likely crashes the device, with residual potential for further memory corruption. The impact is confined to builds using this specific Realtek BEE HCI driver.\n\nThe fix returns early from each error path without unreffing and unrefs the buffer only on the success path, restoring the ownership contract and eliminating both the double-free and the use-after-free read."}, {"lang": "es", "value": "La funci\u00f3n de devoluci\u00f3n de llamada de env\u00edo del controlador HCI Bluetooth BEE de Realtek, bt_hci_bee_send() en drivers/bluetooth/hci/hci_bee.c, viol\u00f3 el contrato de propiedad del b\u00fafer de bt_hci_driver_api. Ese contrato requiere que el controlador consuma (libere la referencia de) el net_buf de transmisi\u00f3n solo en caso de \u00e9xito; en caso de un retorno de error, el llamador del host retiene la propiedad y libera la referencia del b\u00fafer por s\u00ed mismo. El c\u00f3digo anterior a la correcci\u00f3n enrutaba todas las rutas de error a trav\u00e9s de una etiqueta de limpieza compartida que llamaba incondicionalmente a net_buf_unref(buf) antes de devolver el c\u00f3digo de error.\n\nDebido a que las rutas TX del host (en subsys/bluetooth/host/hci_core.c) liberan la referencia del b\u00fafer nuevamente despu\u00e9s de que send() devuelve un error, el b\u00fafer se libera dos veces: el controlador lo devuelve a su grupo net_buf y el host luego libera la referencia del b\u00fafer ya liberado, corrompiendo el grupo compartido / desbordando negativamente el contador de referencias (CWE-415). La misma rama de error desreferenciaba adicionalmente buf -> len dentro de una llamada LOG_ERR despu\u00e9s de que el b\u00fafer ya hab\u00eda sido liberado de su referencia, una lectura de memoria liberada (CWE-416) que se compila en el nivel de registro de errores predeterminado.\n\nLos puntos de fallo se alcanzan cuando la asignaci\u00f3n de b\u00fafer de host a controlador del controlador falla o el env\u00edo del controlador falla (agotamiento de recursos / condiciones de E/S). Un par Bluetooth remoto puede empujar el dispositivo hacia estas condiciones indirectamente al impulsar una intensa actividad de transmisi\u00f3n del host, momento en el cual la doble liberaci\u00f3n corrompe el grupo net_buf del host y muy probablemente bloquea el dispositivo, con potencial residual para una mayor corrupci\u00f3n de memoria. El impacto se limita a las compilaciones que utilizan este controlador HCI BEE de Realtek espec\u00edfico.\n\nLa correcci\u00f3n regresa temprano de cada ruta de error sin liberar la referencia y libera la referencia del b\u00fafer solo en la ruta de \u00e9xito, restaurando el contrato de propiedad y eliminando tanto la doble liberaci\u00f3n como la lectura de uso despu\u00e9s de liberaci\u00f3n."}], "id": "CVE-2026-11894", "lastModified": "2026-10-23T19:10:00.167", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "ADJACENT_NETWORK", "availabilityImpact": "HIGH", "baseScore": 5.9, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H", "version": "3.1"}, "exploitabilityScore": 1.6, "impactScore": 4.2, "source": "vulnerabilities@zephyrproject.org", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-11894", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-08-11T17:04:26.697150Z", "version": "2.0.3"}}]}, "published": "2026-08-11T06:17:11.820", "references": [{"source": "vulnerabilities@zephyrproject.org", "url": "https://github.com/zephyrproject-rtos/zephyr/commit/9a684b5c314fb1d8670b01f7b6c4450a9353906c"}, {"source": "vulnerabilities@zephyrproject.org", "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-v9mj-h2m6-v9c6"}], "sourceIdentifier": "vulnerabilities@zephyrproject.org", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-415"}], "source": "vulnerabilities@zephyrproject.org", "type": "Secondary"}]}

{}

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