CVE-2026-10640
MediumCVSS 4.2Exploitation Probability (EPSS)
Low risk29th percentile - higher than 29% of all known CVEs
Summary
A use-after-free vulnerability was found in Zephyr's IPv6 Neighbor Discovery send paths (NA, NS, RS). After a packet is successfully sent, the code accesses the already-freed packet structure, potentially causing a system crash or limited memory corruption.
Risk Assessment
An unauthenticated on-link attacker can trigger a denial of service by sending Neighbor Solicitation messages to a vulnerable Zephyr device with native IPv6 enabled. In rare cases, limited memory corruption may occur.
Recommendation
Update Zephyr to a version later than 4.4.0 immediately, which contains the fix. If updating is not possible, consider disabling per-interface statistics (CONFIG_NET_STATISTICS_PER_INTERFACE) as a temporary workaround.
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CVE-2026-10676 has been withdrawn as analysis determined that the reported defect is not reachable in any released version of Zephyr.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)
Zephyr's IPv6 Neighbor Discovery send paths (net_ipv6_send_na, net_ipv6_send_ns, net_ipv6_send_rs in subsys/net/ip/ipv6_nbr.c) updated the per-interface ICMP-sent statistics by calling net_pkt_iface(pkt) after net_send_data(pkt) had already returned successfully. On the success path the network stack owns and releases the packet's reference (the L2/driver send unrefs it, e.g. ethernet_send -> net_pkt_unref), so for a freshly allocated packet with refcount 1 the net_pkt slab block can be freed before the statistics line runs (synchronously when no TX queue thread is configured, or via a concurrent TX thread otherwise). The subsequent net_pkt_iface(pkt) reads pkt->iface from the freed slab block, and with CONFIG_NET_STATISTICS_PER_INTERFACE enabled that loaded pointer is dereferenced to increment iface->stats.icmp.sent, a use-after-free (CWE-416). If the slab block was reallocated in the meantime the read/increment targets unrelated or attacker-influenced memory, yielding corrupted statistics, a fault/crash (denial of service), or potential limited memory corruption. The vulnerable Neighbor Advertisement path is reachable by any unauthenticated on-link node simply by sending ICMPv6 Neighbor Solicitations to a Zephyr node with native IPv6 enabled (handle_ns_input -> net_ipv6_send_na). Affected from v3.3.0 through v4.4.0; the fix uses the already-available iface argument instead of touching the sent packet. Configurations without per-interface statistics dereference only a global counter and are not affected by the memory-safety aspect.