CVE-2026-10637
MediumCVSS 5.9Exploitation Probability (EPSS)
Low risk22th percentile - higher than 22% of all known CVEs
Summary
In the Zephyr network stack, the mld_send() function reads the network interface from a packet after it has been freed by the L2 driver. This can lead to a use-after-free condition, potentially causing a NULL-pointer dereference or memory corruption if the freed slot is concurrently reallocated.
Risk Assessment
An unauthenticated attacker on the local link can trigger a denial of service of the networking stack by sending an MLDv2 General Query. There is also a limited possibility of memory corruption.
Recommendation
Apply the fix that caches the interface pointer before sending and no longer touches the packet after net_send_data(). Update to a patched version of Zephyr.
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CVE-2026-10676 has been withdrawn as analysis determined that the reported defect is not reachable in any released version of Zephyr.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-2026-13735Low
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.
- CVE-2026-13734Medium
Vulnerability in Zephyr's WireGuard VPN: wg_process_data_message() validated the anti-replay counter too late, after committing peer-state changes (address update, timers, key rotation). An attacker can re-inject a captured packet, leading to endpoint hijacking and session disruption.
- CVE-2026-13212High
The Zephyr virtio driver does not validate the descriptor-chain head id written by the virtio device into the used ring. A malicious virtio backend can supply an out-of-range id, causing an out-of-bounds read and invocation of an attacker-controlled function pointer in the guest's interrupt context. This enables control-flow hijacking or a reliable crash.
- CVE-2026-12634Medium
A vulnerability in the NVS backend of the Zephyr settings subsystem (settings_nvs.c) causes an out-of-bounds stack write. The nvs_read() function returns the full entry length, which can exceed the buffer size, and the code uses this value as an index for writing a NUL character, leading to a write past the buffer (CWE-787).
- CVE-2026-12632Medium
A vulnerability in Zephyr RTOS's PTP receive handler allows a remote attacker to trigger an out-of-bounds read by sending a crafted PTP packet with an invalid message type (0xE or 0xF). The lack of an upper-bound check on the msg_size[] array index leads to reading beyond the array and subsequent memory operations, potentially causing a crash or limited memory corruption.
- CVE-2026-12630Medium
Zephyr's 6LoWPAN IPHC uncompression code contains an out-of-bounds read in get_ihpc_inlined_size() (subsys/net/ip/6lo.c). The destination inline size is looked up in da_inline_size_table (13 entries) using an index built from the M, DAC and DAM bits of the IPHC dispatch word; reserved combinations 13, 14 and 15 are not bounds-checked and read past the end of the table.
- CVE-2026-12366High
A use-after-free vulnerability exists in Zephyr's dynamic kernel-object disposal path. The unref_check() function frees object storage when the reference count reaches zero, but for timers (K_OBJ_TIMER) it does not cancel the active timeout, leaving a dangling node in the global timeout queue. When the timer expires, the kernel invokes the expiration handler on freed memory, causing a write to freed heap.
Original NVD description (English source)
subsys/net/ip/ipv6_mld.c:mld_send() read the packet interface via net_pkt_iface(pkt) after net_send_data(pkt) returned successfully. Per the network stack's ownership contract (include/zephyr/net/net_core.h, and the explicit warning in subsys/net/ip/net_core.c:453-460 'do not use pkt after that call'), a successful send transfers ownership of the net_pkt and the L2 driver frees it (e.g. ethernet_send() unrefs the packet on success, subsys/net/l2/ethernet/ethernet.c:790), returning it to its k_mem_slab. The subsequent net_pkt_iface(pkt) is therefore a read of a freed object; the recovered interface pointer is then dereferenced and incremented by the per-interface statistics path (net_stats.h UPDATE_STAT/SET_STAT) when CONFIG_NET_STATISTICS_PER_INTERFACE is enabled. If the freed slot is concurrently reallocated, pkt->iface may read back as NULL (NULL-pointer dereference / crash) or as a stale/garbage pointer (stray increment write / memory corruption). The path is reachable remotely on the local link without authentication: handle_mld_query() (registered for NET_ICMPV6_MLD_QUERY) responds to a valid MLDv2 General Query (unspecified multicast address, hop limit 1) by calling send_mld_report() -> mld_send(). The result is a remotely triggerable denial of service of the networking stack, with a narrow possibility of memory corruption. The fix caches the interface in a local before sending and no longer touches the packet after net_send_data(). The IPv4/IGMP sibling (igmp_send) already used the corrected pattern.