NULL pointer dereference in Zephyrproject Zephyr
CVE-2026-10593
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.003 (20.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 21st percentile — 20.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Zephyrproject Zephyr — versions 4.3.0
Weakness classification (CWE)
References
- github.com/zephyrproject-rtos/zephyr/commit/52f25c903f2926cb1281b50fd79654668e2… (Patch, patch)
- github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-22q8-m94g-2pwh (Exploit, Patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-10593?
- CVE-2026-10593 is a medium-severity vulnerability in Zephyrproject Zephyr, classified under NULL Pointer Dereference. CVSS score: 6.5/10. Published 2026-06-28.
- How severe is CVE-2026-10593?
- Medium severity. CVSS v3 base score is 6.5 out of 10.