CVE-2026-13213
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk6th percentile - higher than 6% of all known CVEs
Summary
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.
Risk Assessment
An attacker with physical proximity (Bluetooth) can repeatedly crash the device, causing denial of service. There is no risk of memory corruption or information disclosure.
Recommendation
Apply the fix that adds an early if (!has.registered) guard in security_changed() to prevent scheduling notification work before the service is registered. Update to a patched version.
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-2026-12633High
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.
- CVE-2026-10682Medium
In Zephyr RTOS versions v3.3.0 through v4.4.1, the userspace verifier function z_vrfy_log_filter_set() performs a signed comparison for the src_id parameter, allowing negative values to be passed. This leads to out-of-bounds read and write in the log_dynamic array, which can be exploited for privilege escalation in supervisor mode.
Original NVD description (English source)
The Hearing Access Service (HAS) GATT server in subsys/bluetooth/audio/has.c installs a connection-callback set unconditionally via BT_CONN_CB_DEFINE, so security_changed() runs for every connection that establishes security even before the application has called bt_has_register(). The service attribute pointers hearing_aid_features_attr, preset_control_point_attr, and active_preset_index_attr remain NULL until bt_has_register() resolves them and sets has.registered. With CONFIG_BT_SETTINGS, settings_set_cb() restores each bonded client's persisted context at boot and unconditionally sets context->flags to BONDED_CLIENT_INIT_FLAGS (non-zero). When a previously bonded peer reconnects and re-establishes security during the startup window before bt_has_register() has been called, security_changed() sees the non-zero flags and schedules notify_work_handler, which calls bt_gatt_is_subscribed() with a still-NULL attribute pointer. That triggers an assertion (__ASSERT(attr, ...) in bt_gatt_is_subscribed()), or a NULL dereference of attr->uuid when assertions are compiled out. The result is a remotely triggerable (Bluetooth, adjacent) crash of the HAS peripheral. Exploitation requires the peer to have previously bonded with the device and to reconnect within the boot-time race window before the application registers the service; a peer that reconnects persistently can prolong the outage. Impact is denial of service only, with no memory corruption or information disclosure. The fix adds an early if (!has.registered) { return; } guard in security_changed(), so no notification work is scheduled until the GATT service is registered and its attribute pointers are valid.

