CVE-2026-9263

The CVE-2026-9263 issue affects Zephyr’s ISO Adaptation Layer (ISOAL) in the Bluetooth controller. The root cause is that framed ISO PDU start segments (sc=0) with len len - 3 to underflow when len is 0–2. This produced an oversized length (up to 253–255) that was passed to isoal_rx_append_to_sdu...

CVE-2026-9263

The Zephyr Bluetooth controller ISO Adaptation Layer subsys/bluetooth/controller/llsw/isoal.c fails to validate the length field of a framed ISO PDU start segment. Per the Bluetooth specification a start segment sc=0 always carries a 3-byte timeoffset, so its segment-header len must be at least...

CVE-2026-10652 Out-of-bounds read in Zephyr DNS resolver TXT/SRV record parsing (unvalidated `rdlength`)

Zephyr's DNS resolver subsys/net/lib/dns parses resource records from DNS responses in dnsunpackanswer, which validated only the fixed RR header type, class, TTL, rdlength and accepted any attacker-declared rdlength, including one extending past the end of the received datagram. The TXT and SRV...

CVE-2026-10652

Zephyr’s DNS resolver (subsys/net/lib/dns) is vulnerable to an out-of-bounds read in TXT/SRV records due to unvalidated rdlength in dns_unpack_answer(). The resolver accepts attacker-declared rdlength that may extend past the datagram end, and dns_validate_record() copies up to rdlength bytes fro...

CVE-2026-10652

Zephyr's DNS resolver subsys/net/lib/dns parses resource records from DNS responses in dnsunpackanswer, which validated only the fixed RR header type, class, TTL, rdlength and accepted any attacker-declared rdlength, including one extending past the end of the received datagram. The TXT and SRV...

PT-2026-53912

The Zephyr net buf library lib/net buf/buf.c manipulated both of its reference counts -- the per-header buf-ref and the per-data-block ref count at the start of each variable/heap data allocation -- with plain non-atomic C operators buf-ref++, if --buf-ref 0, if --ref count. The API is documented...

PT-2026-53914

The asynchronous SNTP client in Zephyr subsys/net/lib/sntp/sntp.c, sntp close async closed the UDP socket file descriptor directly from the calling thread immediately after detaching it from the network socket service, without synchronizing with the socket-service poll thread. The socket service...

CVE-2026-8023

Zephyr's HTTP server subsys/net/lib/http provides a static-filesystem resource type HTTPRESOURCETYPESTATICFS, available when CONFIGFILESYSTEM is enabled that serves files from a configured root directory. Before this fix, both the HTTP/1 and HTTP/2 front-ends placed the raw, attacker-controlled...

CVE-2026-10648

mcumgrserialprocessfrag in subsys/mgmt/mcumgr/transport/src/serialutil.c calls netbufreset on the result of smppacketalloc before checking it for NULL. smppacketalloc uses netbufallocKNOWAIT against the shared MCUmgr packet pool CONFIGMCUMGRTRANSPORTNETBUFCOUNT, default 4, which returns NULL when...

CVE-2026-10648 NULL-pointer dereference in MCUmgr serial/console SMP transport on buffer-pool exhaustion

mcumgrserialprocessfrag in subsys/mgmt/mcumgr/transport/src/serialutil.c calls netbufreset on the result of smppacketalloc before checking it for NULL. smppacketalloc uses netbufallocKNOWAIT against the shared MCUmgr packet pool CONFIGMCUMGRTRANSPORTNETBUFCOUNT, default 4, which returns NULL when...

CVE-2026-8023 Path traversal in Zephyr HTTP server static-filesystem resource handler allows unauthenticated remote arbitrary file read

Zephyr's HTTP server subsys/net/lib/http provides a static-filesystem resource type HTTPRESOURCETYPESTATICFS, available when CONFIGFILESYSTEM is enabled that serves files from a configured root directory. Before this fix, both the HTTP/1 and HTTP/2 front-ends placed the raw, attacker-controlled...

CVE-2026-8023 Path traversal in Zephyr HTTP server static-filesystem resource handler allows unauthenticated remote arbitrary file read

Zephyr's HTTP server subsys/net/lib/http provides a static-filesystem resource type HTTPRESOURCETYPESTATICFS, available when CONFIGFILESYSTEM is enabled that serves files from a configured root directory. Before this fix, both the HTTP/1 and HTTP/2 front-ends placed the raw, attacker-controlled...

CVE-2026-8023 Path traversal in Zephyr HTTP server static-filesystem resource handler allows unauthenticated remote arbitrary file read

Zephyr's HTTP server subsys/net/lib/http provides a static-filesystem resource type HTTPRESOURCETYPESTATICFS, available when CONFIGFILESYSTEM is enabled that serves files from a configured root directory. Before this fix, both the HTTP/1 and HTTP/2 front-ends placed the raw, attacker-controlled...

CVE-2026-8023

Zephyr's HTTP server subsys/net/lib/http provides a static-filesystem resource type HTTPRESOURCETYPESTATICFS, available when CONFIGFILESYSTEM is enabled that serves files from a configured root directory. Before this fix, both the HTTP/1 and HTTP/2 front-ends placed the raw, attacker-controlled...

CVE-2026-8023

CVE-2026-8023 concerns Zephyr’s HTTP server static-filesystem resource handler, where HTTP/1 and HTTP/2 front-ends copied the raw request path into a buffer without removing dot segments. This allowed path traversal to escape the configured web root and read arbitrary files after the filesystem r...

CVE-2026-7656 Broken IPv6 Neighbor Discovery input validation allows spoofed RA/NS/NA acceptance in Zephyr net stack

The IPv6 Neighbor Discovery handlers in subsys/net/ip/ipv6nbr.c handlerainput, handlensinput, handlenainput used an incorrect boolean expression that combined the RFC 4861 validity checks with the ICMPv6 code check using the wrong operator precedence: the form was length/hop/source/target checks ...

CVE-2026-7656 Broken IPv6 Neighbor Discovery input validation allows spoofed RA/NS/NA acceptance in Zephyr net stack

The IPv6 Neighbor Discovery handlers in subsys/net/ip/ipv6nbr.c handlerainput, handlensinput, handlenainput used an incorrect boolean expression that combined the RFC 4861 validity checks with the ICMPv6 code check using the wrong operator precedence: the form was length/hop/source/target checks ...

CVE-2026-7656

The CVE affects Zephyr’s IPv6 Neighbor Discovery in subsys/net/ip/ipv6_nbr.c (handle_ra_input/handle_ns_input/handle_na_input). A faulty boolean combining ND validity checks with ICMPv6 code allowed any ND message with code 0 to bypass Hop Limit==255 and multicast/RS/RA validation, enabling forge...

CVE-2026-7656 Broken IPv6 Neighbor Discovery input validation allows spoofed RA/NS/NA acceptance in Zephyr net stack

The IPv6 Neighbor Discovery handlers in subsys/net/ip/ipv6nbr.c handlerainput, handlensinput, handlenainput used an incorrect boolean expression that combined the RFC 4861 validity checks with the ICMPv6 code check using the wrong operator precedence: the form was 'length/hop/source/target checks...

CVE-2026-10647 Deadlock denial of service in USB CDC-NCM device class on TX enqueue failure

The USB CDC-NCM device class subsys/usb/devicenext/class/usbdcdcncm.c ignores the return value of usbdepenqueue in its ethernet transmit callback cdcncmsend. When the enqueue fails, the function still calls ksemtake&data-syncsem, KFOREVER, blocking on a completion semaphore that is only ever...