CVE-2026-11894

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Source

https://cve.org/CVERecord?id=CVE-2026-11894

Import Source

https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-11894.json

JSON Data

https://api.osv.dev/v1/vulns/CVE-2026-11894

Aliases

GHSA-v9mj-h2m6-v9c6

Published

2026-08-11T05:08:51.464Z

Modified

2026-08-12T15:32:42.570977Z

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 Realtek BEE Bluetooth HCI driver `send()` error paths

Details

The Realtek BEE Bluetooth HCI driver's send callback, bthcibeesend() in drivers/bluetooth/hci/hcibee.c, violated the bthcidriverapi buffer-ownership contract. That contract requires the driver to consume (unref) the transmit netbuf 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 netbufunref(buf) before returning the error code.

Because the host TX paths (in subsys/bluetooth/host/hcicore.c) unref the buffer again after send() returns an error, the buffer is freed twice: the driver returns it to its netbuf 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.

The 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.

The 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.

Database specific

{
    "cwe_ids": [
        "CWE-415"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/11xxx/CVE-2026-11894.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

9a684b5c314fb1d8670b01f7b6c4450a9353906c

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

"2026-08-12T15:32:42Z"

vanir_signatures

[
    {
        "id": "CVE-2026-11894-8ba37d03",
        "deprecated": false,
        "signature_type": "Function",
        "signature_version": "v1",
        "digest": {
            "length": 829.0,
            "function_hash": "119131425461472504598452807028641450597"
        },
        "source": "https://github.com/zephyrproject-rtos/zephyr/commit/9a684b5c314fb1d8670b01f7b6c4450a9353906c",
        "target": {
            "function": "bt_hci_bee_send",
            "file": "drivers/bluetooth/hci/hci_bee.c"
        }
    },
    {
        "id": "CVE-2026-11894-9e148de3",
        "deprecated": false,
        "signature_type": "Line",
        "signature_version": "v1",
        "digest": {
            "threshold": 0.9,
            "line_hashes": [
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                "268955982875366531602834501322476028004",
                "282358671043731624700085476080735483909",
                "311033480098083337141935315199081599241",
                "42990732809530792339706049858403925218",
                "257174183963275335327982665360562356541"
            ]
        },
        "source": "https://github.com/zephyrproject-rtos/zephyr/commit/9a684b5c314fb1d8670b01f7b6c4450a9353906c",
        "target": {
            "file": "drivers/bluetooth/hci/hci_bee.c"
        }
    }
]

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-11894.json"