CVE-2026-10593
MediumCVSS 6.5Exploitation Probability (EPSS)
Low risk8th percentile - higher than 8% of all known CVEs
Summary
In Zephyr Bluetooth LE Audio Basic Audio Profile (BAP) unicast client, a NULL pointer dereference vulnerability exists. The unicast_client_ep_qos_state() function writes attacker-controlled QoS fields through the stream->qos pointer, which can be NULL when the stream is codec-configured but not added to a unicast group. A remote ASCS server can send a GATT notification announcing QoS Configured state while the local endpoint is in Codec Configured state, causing a write through NULL and a system crash.
Risk Assessment
An attacker can remotely cause a denial of service (DoS) by sending a crafted GATT notification, leading to a device crash. The vulnerability affects embedded systems using Zephyr RTOS with Bluetooth LE Audio support.
Recommendation
Immediately update Zephyr RTOS to a patched version (v4.4.1 or later). If updating is not possible, restrict trust to remote ASCS servers or disable the BAP unicast client functionality.
Other vulnerabilities in Zephyr
See all- CVE-2026-19673High
A vulnerability in ethernet_recv() in subsys/net/l2/ethernet/ethernet.c in the Zephyr network stack. When the ethertype is 0x8100 and VLAN is enabled on the interface, the received frame buffer is reinterpreted as an 18-byte net_eth_vlan_hdr without re-checking the length, causing an out-of-bounds read and raising hdr_len to 18. A single unauthenticated frame of 14 to 17 bytes carrying the VLAN ethertype triggers the issue.
- CVE-2026-10772Unknown
This CVE has been rejected as a duplicate. The described vulnerability involved incorrect permission checking in the Bluetooth GATT notify/indicate paths in the Zephyr stack, but was already reported as CVE-2026-2411.
- CVE-2026-10676Unknown
CVE-2026-10676 has been withdrawn as analysis determined that the reported defect is not reachable in any released version of Zephyr. In every supported release, the affected value is corrected before use.
- CVE-2026-5067Critical
Zephyr OS has a memory corruption vulnerability in the HTTP server WebSocket upgrade path. An unauthenticated remote attacker can trigger it by sending a crafted Sec-WebSocket-Key header. The bounded copy does not guarantee NUL termination, leading to out-of-bounds read/write on stack.
- CVE-2026-19935High
A vulnerability in the Zephyr Bluetooth LE stack allows a remote, unauthenticated attacker to trigger a use-after-free in L2CAP CoC channel handling with dynamic PSMs. By sending a data frame followed by a disconnect request, the attacker can cause the system workqueue to process work referencing a freed channel, leading to memory corruption or workqueue corruption.
- CVE-2026-19740Medium
The LLCP implementation in Zephyr's Bluetooth LE Controller retains a receive node after accepting LL_PHY_UPDATE_IND, but invalid-PDU paths fail to release it before completing the procedure. An attacker can send a PDU sequence causing an assertion failure (device crash) or leaking nodes from the receive pool, leading to Bluetooth unavailability until reboot.
- CVE-2026-19669High
A vulnerability in Zephyr's syscall verifiers z_vrfy_fuel_gauge_get_props() and z_vrfy_fuel_gauge_set_props() allocates variable-length arrays on the kernel stack sized directly by an unvalidated caller-supplied len argument. Because no bounds check occurs before allocation and copying, a user-mode thread (with CONFIG_USERSPACE) can trigger an out-of-bounds write in supervisor mode with attacker-controlled length and, on the permitted path, attacker-controlled content.
- CVE-2026-19577High
An out-of-bounds read vulnerability was found in the IPv6 subsystem of the Zephyr stack in net_route_ipv6_packet(). The issue stems from missing validation of whether a neighbor cache entry has a link-layer address before using it. An attacker on the same link can force an unresolved neighbor state and trigger an out-of-bounds read past the address array, potentially causing a system panic or data leak.
- CVE-2026-19186High
In the IEEE 802.15.4 stack in Zephyr, the function ieee802154_decipher_data_frame() does not check if the frame is long enough before computing the payload length. Subtracting the header and authentication tag length from the frame length can underflow, leading to an out-of-bounds read and write. An attacker within radio range can send a short frame, causing memory corruption and system crash.
- CVE-2026-18415Medium
The ieee802154_send() function in Zephyr's network stack copies an outgoing packet into a fixed 125-byte transmit buffer without validating its length. When 6LoWPAN fragmentation is enabled but not required, the missing size check allows an out-of-bounds write past the buffer. The flaw is reachable through NET_AF_PACKET sockets bound to an 802.15.4 interface, including from an unprivileged application thread in CONFIG_USERSPACE builds.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

