{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-11893", "assignerOrgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "state": "PUBLISHED", "assignerShortName": "zephyr", "dateReserved": "2026-06-10T15:13:51.139Z", "datePublished": "2026-08-11T04:42:39.049Z", "dateUpdated": "2026-08-11T04:42:39.049Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "e2e69745-5e70-4e92-8431-deb5529a81ad", "shortName": "zephyr", "dateUpdated": "2026-08-11T04:42:39.049Z"}, "title": "Double free / use-after-free in Bouffalo Lab HCI driver send() error paths (hci_bflb)", "descriptions": [{"lang": "en", "value": "The Bluetooth HCI driver for Bouffalo Lab on-chip BLE controllers (BL60x/BL70x/BL61x), bt_bflb_send() in drivers/bluetooth/hci/hci_bflb.c, violates the bt_hci_driver_api.send() buffer-ownership contract. That contract (documented at include/zephyr/drivers/bluetooth.h) requires the buffer reference to be consumed only on success; on error the caller still owns the reference and unrefs it. The driver instead routed all error paths through a shared label that unconditionally called net_buf_unref(buf) before returning the error code, consuming the buffer on failure as well.\n\nWhen send() returns an error, the host TX path (send_buf() in subsys/bluetooth/host/conn.c) unrefs the same buffer again, believing it still owns it. This double-unref over-decrements the net_buf reference count. Because the buffer is a TX fragment whose destroy callback also decrements its still-queued parent buffer, the parent is freed prematurely while reachable on the connection TX queue, producing a use-after-free and corruption of the shared net_buf pool rather than a benign leak.\n\nThe error conditions are on the host-to-controller transmit path (controller send failure, or an unsupported H:4 packet type), so they are not driven directly by attacker-supplied radio bytes; a remote/adjacent peer can influence them only indirectly, e.g. by inducing controller TX failures under heavy link load. The consequence when reached is BLE-stack denial of service (crash / pool corruption) with possible further memory corruption, bounded to devices using one of these Bouffalo Lab on-chip controllers."}], "affected": [{"vendor": "zephyrproject", "product": "zephyr", "collectionURL": "https://github.com/zephyrproject-rtos/zephyr", "packageName": "zephyr", "defaultStatus": "unaffected", "programFiles": ["drivers/bluetooth/hci/hci_bflb.c"], "versions": [{"version": "4.4.0", "status": "affected", "versionType": "semver", "lessThan": "4.4.2"}]}], "references": [{"url": "https://github.com/zephyrproject-rtos/zephyr/commit/76d92d502b30218aaf11cbbe1be180a317627bb9", "name": "Fix commit", "tags": ["patch"]}, {"url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-ph42-6rqx-728c", "name": "GHSA-ph42-6rqx-728c"}], "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"}}}}

{}

{"affected": [{"affectedData": [{"collectionURL": "https://github.com/zephyrproject-rtos/zephyr", "defaultStatus": "unaffected", "packageName": "zephyr", "product": "zephyr", "programFiles": ["drivers/bluetooth/hci/hci_bflb.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 Bluetooth HCI driver for Bouffalo Lab on-chip BLE controllers (BL60x/BL70x/BL61x), bt_bflb_send() in drivers/bluetooth/hci/hci_bflb.c, violates the bt_hci_driver_api.send() buffer-ownership contract. That contract (documented at include/zephyr/drivers/bluetooth.h) requires the buffer reference to be consumed only on success; on error the caller still owns the reference and unrefs it. The driver instead routed all error paths through a shared label that unconditionally called net_buf_unref(buf) before returning the error code, consuming the buffer on failure as well.\n\nWhen send() returns an error, the host TX path (send_buf() in subsys/bluetooth/host/conn.c) unrefs the same buffer again, believing it still owns it. This double-unref over-decrements the net_buf reference count. Because the buffer is a TX fragment whose destroy callback also decrements its still-queued parent buffer, the parent is freed prematurely while reachable on the connection TX queue, producing a use-after-free and corruption of the shared net_buf pool rather than a benign leak.\n\nThe error conditions are on the host-to-controller transmit path (controller send failure, or an unsupported H:4 packet type), so they are not driven directly by attacker-supplied radio bytes; a remote/adjacent peer can influence them only indirectly, e.g. by inducing controller TX failures under heavy link load. The consequence when reached is BLE-stack denial of service (crash / pool corruption) with possible further memory corruption, bounded to devices using one of these Bouffalo Lab on-chip controllers."}], "id": "CVE-2026-11893", "lastModified": "2026-08-11T05:17:11.567", "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"}]}, "published": "2026-08-11T05:17:11.567", "references": [{"source": "vulnerabilities@zephyrproject.org", "url": "https://github.com/zephyrproject-rtos/zephyr/commit/76d92d502b30218aaf11cbbe1be180a317627bb9"}, {"source": "vulnerabilities@zephyrproject.org", "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-ph42-6rqx-728c"}], "sourceIdentifier": "vulnerabilities@zephyrproject.org", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-415"}], "source": "vulnerabilities@zephyrproject.org", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[4.4.0,4.4.2)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "zephyr", "source": "cna", "vendor": "zephyrproject"}, "product": "zephyr", "vendor": "zephyrproject"}], "created": "2026-08-11T06:30:06.641953+00:00", "updated": "2026-08-11T06:30:06.736078+00:00", "vendors": ["zephyrproject", "zephyrproject$PRODUCT$zephyr"]}