UBUNTU-CVE-2026-82389

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Source
https://ubuntu.com/security/CVE-2026-82389
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-82389.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-82389
Upstream
Published
2026-10-26T17:17:00Z
Modified
2026-10-28T20:16:48Z
Severity
  • 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

In the Bluetooth Classic Hands-Free Profile Audio Gateway role, hfp_ag_create() in subsys/bluetooth/host/classic/hfp_ag.c starts an SDP discovery toward the peer, which links the embedded ag->sdp_param._node into the SDP client's pending request list in subsys/bluetooth/host/classic/sdp.c. If the subsequent bt_rfcomm_dlc_connect() call fails, bt_hfp_ag_connect() cleaned up by memset()-ing the entire AG object while that node was still linked, and while ag->slc_work could still be queued on the system work queue. An in-flight SDP discovery cannot be cancelled — bt_sdp_discover_cancel() is declared in the public header but has no implementation — so the request stays in the list with its func, pool and uuid pointers zeroed. The RFCOMM channel passed to bt_hfp_ag_connect() is taken from the peer's own SDP Hands-Free service record in the normal AG flow (bt_sdp_get_proto_param() performs no range validation, and samples/bluetooth/classic/handsfree_ag feeds the value straight through), so a remote BR/EDR device in radio range that advertises an RFCOMM channel outside the valid range 0x01..0x1e deterministically forces bt_rfcomm_dlc_connect() to fail and reach the wipe. Reading the peer's SDP record requires no pairing, and the peer can also trigger the failure by dropping the ACL or racing an RFCOMM DLC on the same DLCI at the right moment. When the SDP client next advances its request list, sdp_client_discover() dereferences the zeroed parameters — net_buf_alloc(param->pool, …) with a NULL pool and param->uuid->type — and the result-notification paths call through the NULL params->func. Zeroing a linked node also truncates the request list behind a stale tail pointer, and re-arming the freed AG slot re-appends the same node and can produce a self-looping list that hangs the Bluetooth RX thread. The impact is a crash or hang of the Bluetooth stack; the written value is a constant zero at a fixed static address, so no attacker-controlled write is available. Only builds with CONFIG_BT_CLASSIC and CONFIG_BT_HFP_AG that use the Audio Gateway role are affected.

References

Affected packages

Ubuntu:16.04:LTS
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

3.*
3.1.2-1
3.1.2-1build1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libzephyr4",
            "binary_version":  "3.1.2-1build1"
        },
        {
            "binary_name":  "libzephyr4-krb5",
            "binary_version":  "3.1.2-1build1"
        },
        {
            "binary_name":  "zephyr-clients",
            "binary_version":  "3.1.2-1build1"
        },
        {
            "binary_name":  "zephyr-server",
            "binary_version":  "3.1.2-1build1"
        },
        {
            "binary_name":  "zephyr-server-krb5",
            "binary_version":  "3.1.2-1build1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-82389.json"
Ubuntu:18.04:LTS
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

3.*
3.1.2-1build1
3.1.2-1build2

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libzephyr4",
            "binary_version":  "3.1.2-1build2"
        },
        {
            "binary_name":  "libzephyr4-krb5",
            "binary_version":  "3.1.2-1build2"
        },
        {
            "binary_name":  "zephyr-clients",
            "binary_version":  "3.1.2-1build2"
        },
        {
            "binary_name":  "zephyr-server",
            "binary_version":  "3.1.2-1build2"
        },
        {
            "binary_name":  "zephyr-server-krb5",
            "binary_version":  "3.1.2-1build2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-82389.json"
Ubuntu:20.04:LTS
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

3.*
3.1.2-1build3

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libzephyr4",
            "binary_version":  "3.1.2-1build3"
        },
        {
            "binary_name":  "libzephyr4-krb5",
            "binary_version":  "3.1.2-1build3"
        },
        {
            "binary_name":  "zephyr-clients",
            "binary_version":  "3.1.2-1build3"
        },
        {
            "binary_name":  "zephyr-server",
            "binary_version":  "3.1.2-1build3"
        },
        {
            "binary_name":  "zephyr-server-krb5",
            "binary_version":  "3.1.2-1build3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-82389.json"
Ubuntu:22.04:LTS
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

3.*
3.1.2-1build3

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libzephyr4",
            "binary_version":  "3.1.2-1build3"
        },
        {
            "binary_name":  "libzephyr4-krb5",
            "binary_version":  "3.1.2-1build3"
        },
        {
            "binary_name":  "zephyr-clients",
            "binary_version":  "3.1.2-1build3"
        },
        {
            "binary_name":  "zephyr-server",
            "binary_version":  "3.1.2-1build3"
        },
        {
            "binary_name":  "zephyr-server-krb5",
            "binary_version":  "3.1.2-1build3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-82389.json"
Ubuntu:24.04:LTS
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

3.*
3.1.2-1.1
3.1.2-1.1build1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libzephyr4",
            "binary_version":  "3.1.2-1.1build1"
        },
        {
            "binary_name":  "libzephyr4-krb5",
            "binary_version":  "3.1.2-1.1build1"
        },
        {
            "binary_name":  "zephyr-clients",
            "binary_version":  "3.1.2-1.1build1"
        },
        {
            "binary_name":  "zephyr-server",
            "binary_version":  "3.1.2-1.1build1"
        },
        {
            "binary_name":  "zephyr-server-krb5",
            "binary_version":  "3.1.2-1.1build1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-82389.json"
Ubuntu:26.04:LTS
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

3.*
3.1.2-1.1build1
3.1.2-4

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libzephyr4",
            "binary_version":  "3.1.2-4"
        },
        {
            "binary_name":  "libzephyr4-krb5",
            "binary_version":  "3.1.2-4"
        },
        {
            "binary_name":  "zephyr-clients",
            "binary_version":  "3.1.2-4"
        },
        {
            "binary_name":  "zephyr-server",
            "binary_version":  "3.1.2-4"
        },
        {
            "binary_name":  "zephyr-server-krb5",
            "binary_version":  "3.1.2-4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-82389.json"
Ubuntu:26.10
zephyr

Package

Name
zephyr
Purl
pkg:deb/ubuntu/zephyr?arch=source&distro=stonking

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

3.*
3.1.2-4

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libzephyr4",
            "binary_version":  "3.1.2-4"
        },
        {
            "binary_name":  "libzephyr4-krb5",
            "binary_version":  "3.1.2-4"
        },
        {
            "binary_name":  "zephyr-clients",
            "binary_version":  "3.1.2-4"
        },
        {
            "binary_name":  "zephyr-server",
            "binary_version":  "3.1.2-4"
        },
        {
            "binary_name":  "zephyr-server-krb5",
            "binary_version":  "3.1.2-4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-82389.json"