CVE-2026-10660
MediumCVSS 6.4Exploitation Probability (EPSS)
Low risk5th percentile - higher than 5% of all known CVEs
Summary
A vulnerability in the Bluetooth BAP Broadcast Assistant GATT client in Zephyr RTOS causes buffer overflow and cross-connection data corruption. A shared 512-byte buffer for all connection instances, combined with concurrent notifications from multiple Scan Delegator devices, can lead to out-of-bounds writes and data mixing between connections.
Risk Assessment
An attacker over Bluetooth Low Energy can exploit this vulnerability to cause system crashes (denial of service) or memory corruption, potentially leading to unpredictable device behavior. The risk applies to devices acting as Broadcast Assistant with multiple connections.
Recommendation
Immediately update Zephyr RTOS to a version containing the fix (v4.4.1 or later). If an update is not possible, limit the number of concurrent BLE connections or disable the Broadcast Assistant feature.
Other vulnerabilities in Zephyr RTOS
See all- CVE-2026-13480Low
A vulnerability in the LoRaWAN TS004 Fragmented Data Block Transport handler frag_transport_package_callback() in Zephyr RTOS (subsys/lorawan/services/frag_transport.c) lacks validation of remaining payload bytes before each access. An attacker with session keys can cause an out-of-bounds read (up to ~232 bytes) past the RxPayload buffer, copying adjacent static memory into decoder buffers and the FUOTA flash image.
- CVE-2026-13213Medium
A vulnerability in the Hearing Access Service (HAS) in Zephyr RTOS allows a remote (Bluetooth) crash of the HAS peripheral. The issue occurs when a previously bonded client reconnects during the startup window before the application registers the service, leading to an assertion or NULL pointer dereference.
- CVE-2026-12633High
Vulnerability in IPv6 neighbor-discovery code (subsys/net/ip/ipv6_nbr.c) in Zephyr RTOS. The handle_ra_6co() function does not bound the context_len field from the 6CO option in Router Advertisements, leading to a buffer overflow and out-of-bounds memset. An attacker on the same link can send a crafted packet causing a system crash.
- CVE-2026-9771High
A vulnerability in the flash_copy() system call in Zephyr RTOS (with CONFIG_USERSPACE enabled) allows an unprivileged thread to pass forged pointers to flash device structures. Lack of device object validation (src_dev, dst_dev) before dereferencing enables arbitrary code execution in supervisor mode, leading to privilege escalation outside the userspace sandbox.
- CVE-2026-12364High
The vulnerability in Zephyr RTOS concerns the system-call verifier z_vrfy_z_log_msg_static_create(), which did not validate arguments passed to the kernel function. This allows an unprivileged user thread to supply arbitrary pointers and lengths, leading to kernel memory reads and system crashes.
- CVE-2026-12363Medium
The LoRaWAN Fragmented Data Block Transport service (frag_transport.c) does not validate the fragment counter in a received DATA_FRAGMENT command before forwarding it to the decoder. A frag_counter of 0 causes an underflow (frag_counter - 1), leading to an out-of-bounds write (CWE-787) in the default Semtech/LoRaMAC-node decoder, corrupting decoder state and disrupting the firmware-update (FUOTA) session.
- CVE-2026-12233Medium
The PSA Protected Storage credential backend (subsys/net/lib/tls_credentials/tls_credentials_trusted.c) declared its credential-store mutex as a plain zero-filled static struct k_mutex credential_lock; and never called k_mutex_init() on it. A statically zero-filled k_mutex has an uninitialized wait queue (its dlist head/tail are NULL instead of the self-referential sentinels that k_mutex_init/K_MUTEX_DEFINE install). The uncontended lock path does not touch the wait queue, so the defect is latent and serialized use behaves correctly.
- CVE-2026-11812Low
The vulnerability in the UpdateHub subsystem (subsys/mgmt/updatehub/updatehub.c) is due to unsynchronized access to the shared ctx structure. Concurrent operations (background autohandler and user-triggered calls) can write past the fds[1] array, overwriting adjacent struct fields, leading to internal state corruption and denial of service in the firmware update path.
- CVE-2026-10849High
The hawkBit device management client in Zephyr RTOS has a heap-based out-of-bounds write vulnerability. The response buffer lacks space for a terminating null byte, causing a single null byte write past the allocated memory when the response length matches the buffer size.
- CVE-2026-10848High
In the OCPP 1.6 client in Zephyr RTOS, a vulnerability was found involving out-of-bounds buffer read during WAMP RPC frame parsing. The extract_string_field() function uses strncpy without guaranteed null-termination, leading to reads beyond the 128-byte buffer and potential out-of-bounds null write. The vulnerability can be remotely exploited by a malicious central server or an on-path attacker.
Original NVD description (English source)
The Bluetooth BAP Broadcast Assistant GATT client in subsys/bluetooth/audio/bap_broadcast_assistant.c reassembled remote Broadcast Receive State data into a single file-static net_buf_simple (att_buf, BT_ATT_MAX_ATTRIBUTE_LEN = 512 bytes) shared by all connection instances, while the BUSY flag, long-read handle, and reset/offset state were per-connection. When the device acts as a Broadcast Assistant connected to multiple Scan Delegator peripherals, notification and long-read callbacks from different connections interleave on the shared buffer: the append in notify_handler (net_buf_simple_add_mem at the not-busy branch) performs no tailroom check, so receive-state notifications from two or more delegators accumulate on the same 512-byte buffer and, with a sufficiently large configured ATT MTU (BT_L2CAP_TX_MTU up to 2000) and two-to-three concurrent connections, write past the buffer into adjacent .bss (net_buf_simple_add only asserts in debug builds). Even below the overflow threshold, one connection's net_buf_simple_reset zeroes the shared length while another connection's reassembly and GATT read offset are in flight, mixing one peer's data into another's parse. A malicious or compromised Scan Delegator (or two colluding peers) over BLE can trigger this, causing out-of-bounds writes (memory corruption / denial of service) and cross-connection data corruption. The fix moves the buffer into the per-connection instance struct so each connection reassembles into its own buffer. Affects Zephyr releases shipping the Broadcast Assistant with the shared buffer, including v4.4.0 and earlier.

