zephyrproject zephyr up to 4.4.x bap_unicast_client.c unicast_client_ep_qos_state null pointer dereference

Summaryinfo

A vulnerability classified as problematic has been found in zephyrproject zephyr up to 4.4.x. The impacted element is the function unicast_client_ep_qos_state of the file subsys/bluetooth/audio/bap_unicast_client.c. The manipulation leads to null pointer dereference. This vulnerability is listed as CVE-2026-10593. The attack must be carried out from within the local network. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in zephyrproject zephyr up to 4.4.x and classified as problematic. This issue affects the function unicast_client_ep_qos_state of the file subsys/bluetooth/audio/bap_unicast_client.c. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. The summary by CVE is:

The Zephyr Bluetooth LE Audio Basic Audio Profile (BAP) unicast client mishandles peer-supplied ASE state notifications. In unicast_client_ep_qos_state() (subsys/bluetooth/audio/bap_unicast_client.c), the handler writes attacker-controlled QoS fields (interval, framing, phy, sdu, rtn, latency, pd) through the stream-qos pointer with only a stream != NULL guard. stream-qos is NULL for any stream that has been codec-configured via bt_bap_stream_config() but not yet added to a unicast group (it is set only by unicast_group_add_stream()). A malicious or buggy remote ASCS server, to which the local device is connected as a BAP unicast client, can send a GATT notification announcing the ASE has entered the QoS Configured state while the local endpoint is still in the Codec Configured state — a transition the dispatcher explicitly permits — during that window, causing a write through a NULL pointer and a crash (denial of service). The data written is itself remote-controlled. The defect shipped in v4.3.0 and v4.4.0 (and earlier). The fix re-points all BAP QoS storage to the always-valid embedded ep-qos struct, eliminating the NULL dereference.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-10593 since 06/01/2026. The exploitation is known to be easy. Access to the local network is required for this attack to succeed. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available.

Upgrading to version 4.5.0 eliminates this vulnerability. Applying the patch 52f25c903f2926cb1281b50fd79654668e2d483f is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-39981). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Project Management Software

Vendor

• zephyrproject

Name

• zephyr

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4

License

• open-source

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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