CVE-2026-13480
LowCVSS 3.1Exploitation Probability (EPSS)
Low risk6th percentile - higher than 6% of all known CVEs
Summary
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.
Risk Assessment
The risk to the organization is a limited memory disclosure (e.g., keys, configuration data) due to an out-of-bounds read. However, this requires possession of session keys, so the real threat is mainly in scenarios where keys have been compromised.
Recommendation
Apply the vendor-provided fix immediately (adding remaining-length guards before each access). If the fix is unavailable, restrict trust in the FUOTA server and monitor session key integrity.
Other vulnerabilities in Zephyr RTOS
See all- CVE-2026-82962Medium
A vulnerability in ethernet_fill_header() in the Zephyr RTOS network stack prepends the Ethernet header in place via net_buf_push without verifying that the packet has sufficient headroom. Packets allocated by a different L2 (e.g., 802.15.4/OpenThread, PPP) and handed to Ethernet through routing or tunnelling have too little (usually zero) headroom, causing an out-of-bounds write. In builds without CONFIG_ASSERT and CONFIG_NET_BUF_HARDENING this results in memory corruption.
- CVE-2026-19595Medium
A vulnerability in the Zephyr RTOS syscall verifier: z_vrfy_rtio_cqe_get_mempool_buffer() validated its output parameters buff and buff_len with K_SYSCALL_MEMORY_READ() instead of K_SYSCALL_MEMORY_WRITE(). This allows an unprivileged user-mode thread to invoke the syscall with pointers to read-only memory, causing a supervisor-mode store outside the permitted region or a kernel fault that halts or reboots the device.
- CVE-2026-19940Medium
A vulnerability in the Bluetooth Classic Hands-Free Profile Audio Gateway (HFP AG) implementation in Zephyr RTOS causes corruption of the kernel timeout list. By sending AT+CIND? and quickly reconnecting, a remote attacker can trigger a system-wide fault or hang.
- CVE-2026-19736High
The NXP MCUX TRNG entropy driver in Zephyr (drivers/entropy/entropy_mcux_trng.c) passes the caller's byte count directly to the SDK routine TRNG_GetRandomData(), which on i.MX RT5xx/RT6xx parts always copies whole 32-bit words and rounds entropy draws up to a multiple of 128 bytes. A request length not a multiple of four causes an underflow in the SDK's buffer-full check, leading to an overflow of up to 127 bytes past the caller's buffer.
- CVE-2026-19575High
A vulnerability in Zephyr RTOS affects the user-mode verification handler z_vrfy_device_deinit() in kernel/device.c, which validated its dev argument with K_SYSCALL_OBJ_INIT(dev, K_OBJ_ANY). Because k_object_validate() short-circuits type comparison for K_OBJ_ANY, the check only verified that the pointer was the base address of some kernel object the calling thread was granted, without comparing the object's actual type. This allows a local user-mode thread to pass a thread stack object (e.g., from k_thread_stack_alloc()) and achieve supervisor-mode kernel code execution.
- CVE-2026-19574High
In the ARM64 MMU back-end of Zephyr RTOS, address space identifiers (ASIDs) are assigned by a bare round-robin counter, which after wrapping past 255 possible values can hand the same ASID to a new domain while a still-live domain holds it. Because domain-private mappings are installed as non-global (MT_NG), the ASID is the only tag separating cached translations in the TLB, and the context-switch path does not flush the TLB for a duplicate reached through a third domain. As a result, user-mode threads in one domain can read and write memory belonging to another domain, defeating memory-domain isolation.
- CVE-2026-19569High
A vulnerability in the Zephyr RTOS kernel allows an unprivileged user-mode thread to perform an out-of-bounds write in kernel memory. It stems from missing overflow checks when calculating allocation sizes for dynamic kernel objects, leading to undersized heap allocations. An attacker can exploit this to escalate privileges and execute arbitrary code at the kernel level.
- CVE-2026-19185High
A vulnerability was found in the system-call verifier for i3c_do_ccc() in Zephyr RTOS, which fails to validate per-target data pointers in the i3c_ccc_payload structure. The verifier also operates on the caller's live structure, allowing another thread to modify fields between check and use. This allows an unprivileged thread to write to arbitrary kernel addresses (via read CCC) or disclose kernel memory (via write CCC), leading to privilege escalation.
- CVE-2026-18747Medium
A vulnerability in the SMP-over-console transport in Zephyr RTOS allows an unauthenticated attacker to trigger a buffer length underflow by sending a single 7-byte frame to the management console. This leads to an out-of-bounds read, potentially causing a denial of service on the MCUmgr thread or memory disclosure.
- CVE-2026-18417Medium
In Zephyr RTOS, a vulnerability exists in the BSD socket layer where an asynchronous error was stored in the user_data field of the network context, which for listening TCP sockets is used to store a pointer to the parent context. In v4.3.0, after an interface-down event, the accept callback was not disarmed, leading to reuse of the poisoned value as a pointer and writes to an invalid address, causing a kernel fatal error (device crash or reset).
Original NVD description (English source)
The LoRaWAN TS004 Fragmented Data Block Transport handler frag_transport_package_callback() in subsys/lorawan/services/frag_transport.c parses downlink command bytes without validating that enough payload bytes remain before each access. The loop's only bound is rx_pos < len; after consuming the one-byte command id the handler cast rx_buf + rx_pos to a 10-byte struct frag_transport_setup_req, and for a DATA_FRAGMENT command passed &rx_buf[rx_pos] to the fragment decoder, which reads exactly ctx.frag_size bytes — with no remaining-length check in either case. The fragment size is attacker-chosen in a preceding FRAG_SESSION_SETUP command (ctx.frag_size = req->frag_size, capped at CONFIG_LORAWAN_FRAG_TRANSPORT_MAX_FRAG_SIZE, default 232). rx_buf aliases the 255-byte static MacCtx.RxPayload buffer in the loramac-node MAC layer, while len is the actual decrypted payload length. By padding a downlink with mismatched-index DATA_FRAGMENT filler commands (each advancing rx_pos by three bytes without producing an answer) and appending one matching-index fragment near the end of the payload, an attacker can make the decoder read up to roughly frag_size bytes past the end of RxPayload, copying adjacent static memory into the decoder buffers and the FUOTA flash image. The handler runs only on downlinks that have already passed the LoRaWAN frame MIC and FRMPayload decryption, so the defect is reachable only by a party holding the device's session keys (the FUOTA server or an attacker who has compromised those keys). The out-of-bounds bytes are never returned to the sender — the only uplink emitted is a status answer carrying fragment counts — so there is no direct disclosure channel, and on typical flat-memory LoRaWAN MCUs the over-read stays within mapped memory, making a crash unlikely. The impact is therefore a bounded out-of-bounds read with limited confidentiality consequence and no write or control-flow primitive. The fix adds remaining-length guards before each access.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS