CVE-2026-11893

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Source

https://cve.org/CVERecord?id=CVE-2026-11893

Import Source

https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-11893.json

JSON Data

https://api.osv.dev/v1/vulns/CVE-2026-11893

Aliases

GHSA-ph42-6rqx-728c

Published

2026-08-11T04:42:39.049Z

Modified

2026-08-13T08:22:29.110888Z

Severity

5.9 (Medium) CVSS_V3 - CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H CVSS Calculator

Summary

Double free / use-after-free in Bouffalo Lab HCI driver send() error paths (hci_bflb)

Details

The Bluetooth HCI driver for Bouffalo Lab on-chip BLE controllers (BL60x/BL70x/BL61x), btbflbsend() in drivers/bluetooth/hci/hcibflb.c, violates the bthcidriverapi.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 netbufunref(buf) before returning the error code, consuming the buffer on failure as well.

When send() returns an error, the host TX path (sendbuf() in subsys/bluetooth/host/conn.c) unrefs the same buffer again, believing it still owns it. This double-unref over-decrements the netbuf 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.

The 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.

Database specific

{
    "cwe_ids": [
        "CWE-415"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/11xxx/CVE-2026-11893.json",
    "cna_assigner": "zephyr"
}

References

Affected packages

Git / github.com/zephyrproject-rtos/zephyr

Affected ranges

Type

GIT

Repo

https://github.com/zephyrproject-rtos/zephyr

Events

Introduced

684c9e8f32e4373a21098559f748f06915f950c9

Fixed

76d92d502b30218aaf11cbbe1be180a317627bb9

Database specific

Show details

{
    "extracted_events": [
        {
            "introduced": "4.4.0"
        },
        {
            "fixed": "4.4.2"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "REFERENCES"
    ]
}

Affected versions

v4.*

v4.4.0

Database specific

vanir_signatures_modified

"2026-08-13T08:22:29Z"

vanir_signatures

[
    {
        "id": "CVE-2026-11893-15ac4de3",
        "deprecated": false,
        "signature_type": "Function",
        "signature_version": "v1",
        "digest": {
            "length": 1265.0,
            "function_hash": "226881773454050183551403034836331380422"
        },
        "source": "https://github.com/zephyrproject-rtos/zephyr/commit/76d92d502b30218aaf11cbbe1be180a317627bb9",
        "target": {
            "function": "bt_bflb_send",
            "file": "drivers/bluetooth/hci/hci_bflb.c"
        }
    },
    {
        "id": "CVE-2026-11893-ad9893cb",
        "deprecated": false,
        "signature_type": "Line",
        "signature_version": "v1",
        "digest": {
            "threshold": 0.9,
            "line_hashes": [
                "18072795392702696080439128071587689539",
                "198813787744207654215890589728897653937",
                "158820056818590277024230035500344846713",
                "12750591706990312482651231946681551694",
                "63213941988012335124585242776049842396",
                "41448333500293620719504467010327834494",
                "239981764917559746895776441528409519134",
                "103431136381742620376045719852805650016",
                "320592333589621037973354445665561012360",
                "331816988530001928164642018194830563780",
                "304743550420815742830272304802414051188",
                "2000398518571480097176141820631283744",
                "166285958029737031287767396829097906739",
                "19456876009473520948894821128434440693",
                "156004365950532716655313983041051826353",
                "265230963830787615286421467234495083070",
                "109999722085655267975804195666368615607",
                "15156075185953405868213754404250594802",
                "245636040323895663722919768696811738496",
                "24446558233427148883025457253823405746",
                "47758802025733740376791157932106408890",
                "297810030243082583196032295188160182964",
                "149661323100771570217732091394925549871",
                "259706831093528235814162339650300558281"
            ]
        },
        "source": "https://github.com/zephyrproject-rtos/zephyr/commit/76d92d502b30218aaf11cbbe1be180a317627bb9",
        "target": {
            "file": "drivers/bluetooth/hci/hci_bflb.c"
        }
    }
]

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-11893.json"