CVE-2026-15460
MediumCVSS 5.4Exploitation Probability (EPSS)
Low risk5th percentile - higher than 5% of all known CVEs
Summary
A vulnerability in the Bluetooth Classic (BR/EDR) stack in Zephyr RTOS affects the L2CAP receive handler, which dispatches inbound data PDUs based only on the destination channel ID without verifying that the channel has reached the BT_L2CAP_CONNECTED state. An attacker within radio range can send data to a channel during connection setup, before configuration and authentication complete. This can lead to delivery of attacker data to upper-layer protocols on a half-open channel and to use of stale or partially initialized channel state, causing denial of service or a potential dangling-pointer condition.
Risk Assessment
The risk includes remote denial-of-service attacks on Bluetooth Classic devices and potential data integrity or privilege escalation by delivering malicious data to upper-layer protocols on an unauthenticated channel. In extreme cases, a dangling pointer may be exploited, leading to uncontrolled system behavior.
Recommendation
Apply the vendor-provided fix (Zephyr) immediately, which adds a channel state check before processing data. Update the system to a patched version and ensure all Bluetooth Classic devices are updated.
Other vulnerabilities in Zephyr
See all- 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CVE-2026-10676 has been withdrawn as analysis determined that the reported defect is not reachable in any released version of Zephyr.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-2026-15890Medium
A vulnerability in the PSA Internal Trusted Storage module in Zephyr involves a lack of synchronization in nonce generation for AEAD encryption. The function secure_storage_its_transform_aead_get_nonce() uses unsynchronized function-local static variables, and concurrent writes to the same UID can lead to nonce reuse with the same key. This causes a catastrophic AEAD failure, enabling data leakage and forgery of stored entries.
- CVE-2026-17050Medium
The experimental USB host stack in Zephyr contains a double-free vulnerability in the configuration descriptor buffer. On three error paths, the buffer is freed but the pointer is left dangling, leading to a second free during cleanup. The vulnerability can be triggered by a malicious or malformed USB device.
- CVE-2026-16515Medium
The net_icmpv6_send_error() function in the Zephyr network stack implemented only one of the three RFC 4443 section 2.4 suppression rules, so it did not check whether the packet's source address identifies a single node or whether the packet was sent to a multicast destination. An unauthenticated attacker on the same link can send a single IPv6 packet to ff02::1 with a spoofed victim source, causing every Zephyr node to emit ICMPv6 Parameter Problem messages to that victim (reflection with amplification), or send a unicast packet with a multicast source address, turning it into a link-flooding multicast frame.
- CVE-2026-15924Medium
Zephyr's TLS socket layer (subsys/net/lib/sockets/sockets_tls.c) keeps a process-global client_cache array of cached client session buffers shared by every TLS socket, with access serialized only by the per-socket ctx->lock mutex. Because CONFIG_NET_SOCKETS_TLS_MAX_CLIENT_SESSION_COUNT defaults to 1, two concurrent client sockets contend for the same slot, causing a use-after-free read and a double-free when two saves evict the same entry. This corrupts the mbedTLS heap; the fix adds a dedicated session_cache_lock mutex taken across every accessor of client_cache.
- CVE-2026-15923Medium
The Zephyr SDIO subsystem has a vulnerability in sdio_io_rw_extended_helper() where func->cis.max_blk_size is decoded from the SDIO card without validation. If a card reports a maximum block size of zero, the transfer loop never terminates, causing a thread hang and permanent mutex lock, leading to denial of service for the SDIO peripheral.
- CVE-2026-14697Medium
In the IPv6 subsystem of the Zephyr stack (subsys/net/ip/ipv6_nbr.c), the net_ipv6_send_ns() function allocates a transmit net_pkt for a Neighbor Solicitation. When called with a data packet pending on an unresolved neighbor and the neighbor's pending_queue is already non-empty, the function appends the data packet and returns early without sending the NS via net_send_data() or releasing it with net_pkt_unref(). The freshly allocated NS net_pkt and its attached TX buffers are held only by a local variable and are leaked permanently, never returning to CONFIG_NET_PKT_TX_COUNT / CONFIG_NET_BUF_TX_COUNT.
- CVE-2026-13735Low
Zephyr's WireGuard implementation mishandled keepalive packets. A type-4 message with a 16-byte payload (empty plaintext plus Poly1305 tag) was accepted without tag verification because wg_process_data_message() returned early before calling wg_decrypt_packet(). An attacker could send a forged keepalive without knowing the session key.
Original NVD description (English source)
The Bluetooth Classic (BR/EDR) L2CAP receive handler bt_l2cap_br_recv() in subsys/bluetooth/host/classic/l2cap_br.c dispatched inbound data PDUs based only on the destination channel ID, without checking that the target channel had reached the BT_L2CAP_CONNECTED state. A dynamic channel is assigned its RX CID and added to the connection's channel list while still in BT_L2CAP_CONNECTING (and later BT_L2CAP_CONFIG) — before configuration completes and, for PSMs that require security, before the peer is authenticated (l2cap_br_conn_req()). Because the channel is already findable by bt_l2cap_br_lookup_rx_cid() during this window, a remote peer within radio range can send a data PDU addressed to that CID and have it processed on a not-yet-established channel. The dispatch keys off channel fields (BR_CHAN(chan)->rx.mode, rx.mps) that are only initialized during configuration by l2cap_br_conf(); since channel objects are pooled and bt_l2cap_br_chan_del() does not reset rx.mode or the reassembly buffer _sdu, a reused channel can carry stale state into the CONNECTING window and route the frame into the retransmission/flow-control path (bt_l2cap_br_ret_fc_recv()) with stale parameters and a possibly stale _sdu pointer. The impact is delivery of attacker data to upper-layer protocol handlers on a half-open (and possibly unauthenticated) channel, plus operation on stale or partially initialized channel state on reused channel objects — leading to channel/link teardown (denial of service) and, in the stale-_sdu case, a dangling-pointer condition. The fix adds an explicit BR_CHAN(chan)->state < BT_L2CAP_CONNECTED guard that drops any data received before the channel is fully connected.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

