Zephyrproject

CVE	Summary	Severity	CVSS	EPSS	Priority	Signals
CVE-2026-1678	Buffer overflow in Zephyr RTOS dns_unpack_name() function causing OOB writes. PoC available.	CRITICAL	9.4	0.1%	67	PoC No patch
CVE-2026-12233	Concurrent TLS handshakes on Zephyr RTOS devices built with CONFIG_TLS_CREDENTIALS_BACKEND_PROTECTED_STORAGE cause a deterministic kernel panic and device reset via a NULL pointer dereference in the uninitialized credential mutex wait queue. The PSA Protected Storage credential backend in all affected Zephyr builds declared its serialization mutex without proper initialization, leaving its dlist sentinels as NULL; the fault triggers only on first contention but is fully deterministic once two threads race to acquire the lock. No public exploit has been identified and the issue is not in CISA KEV, though no exploit sophistication is required beyond opening multiple simultaneous TLS connections.	MEDIUM	5.9	31.0%	60
CVE-2026-7656	Forged IPv6 Neighbor Discovery acceptance in the Zephyr RTOS network stack (all releases through v4.4.0) lets an adjacent on-link attacker inject spoofed Router Advertisement, Neighbor Solicitation, and Neighbor Advertisement messages because an operator-precedence bug in subsys/net/ip/ipv6_nbr.c silently skips every RFC 4861 sanity check whenever the (always-present) ICMPv6 code is 0. Because the bypassed checks include the Hop-Limit==255 on-link proof, even off-link/remote attackers may have forged ND packets accepted, enabling default-router/DNS/SLAAC hijacking and neighbor-cache poisoning for man-in-the-middle, redirection, and denial of service. A vendor patch exists (commit 095f064c) but there is no public exploit identified at time of analysis and the issue is not in CISA KEV.	MEDIUM	6.8	0.2%	54	PoC
CVE-2026-13214	Remote code execution and denial of service in the Zephyr RTOS OCPP 1.6 client (subsys/net/lib/ocpp) allows an attacker who controls or man-in-the-middles the central system endpoint to smash the OCPP reader thread's stack. A malicious GetConfiguration message with an over-long JSON "key" field triggers an unbounded strcpy() into a fixed 50-byte stack buffer, corrupting the reader thread's stack with attacker-chosen bytes. A vendor patch exists and no public exploit has been identified at time of analysis; CVSS is rated 9.8, though real-world reach is bounded by the OCPP-charging-station niche.	CRITICAL	9.8	0.5%	50
CVE-2026-10666	Stack out-of-bounds write in the Zephyr RTOS network IP-parsing utility (parse_ipv4() in subsys/net/ip/utils.c) lets a crafted "a.b.c.d:port" address string with an overlong post-colon suffix overflow a 17-byte stack buffer with fully attacker-controlled length and contents, affecting Zephyr 1.9.0 through 4.4.0. Any application that resolves a network-influenced address string via the standard socket API (zsock_getaddrinfo/literal resolution), DNS server-string configuration, or the eswifi Wi-Fi DNS-response path is exposed, yielding at minimum denial of service and potentially control-flow hijack. No public exploit identified at time of analysis and it is not listed in CISA KEV; SSVC records proof-of-concept maturity and EPSS is low at 0.35%.	CRITICAL	9.8	0.3%	49
CVE-2026-5067	Remote code execution and denial of service in Zephyr RTOS HTTP server (versions 3.7.0 through 4.3.0) allow unauthenticated network attackers to corrupt stack memory by sending a crafted Sec-WebSocket-Key header during WebSocket upgrade. The flaw is a CWE-170 improper NUL-termination issue where a bounded copy fails to terminate the header buffer, causing strlen() and subsequent concatenation to read and write past stack bounds. No public exploit identified at time of analysis, but the CVSS 9.8 rating and trivially reachable attack surface make this a high-priority issue for any Zephyr deployment with CONFIG_HTTP_SERVER_WEBSOCKET enabled.	CRITICAL	9.8	0.2%	49	No patch
CVE-2026-12234	Kernel heap corruption via a double-fetch race condition in Zephyr RTOS's unprivileged socket syscall verifiers allows a local low-privilege attacker to achieve kernel privilege escalation or trigger a kernel denial of service. The flaw exists in z_vrfy_zsock_sendmsg() and z_vrfy_zsock_recvmsg() within subsys/net/lib/sockets/sockets.c, where msg_iovlen is read twice from live user memory - once to size the kernel heap shadow buffer and once as the iovec copy-loop bound - enabling a cooperating attacker thread to inflate the field between those reads and drive an out-of-bounds write into adjacent kernel heap objects. No public exploit has been identified at time of analysis; an upstream patch commit is confirmed available via the Zephyr project security advisory.	HIGH	7.8	8.0%	47
CVE-2026-10672	Out-of-bounds read in the Zephyr RTOS LwM2M firmware-update pull client (lwm2m_pull_context.c) lets a malicious or compromised LwM2M management server - or an on-path attacker on a session without strong DTLS - leak adjacent device memory and crash devices by writing an over-long firmware Package URI (/5/0/1). Because the Firmware-Update object stores the URI in a 255-byte buffer but the pull context copies exactly 128 bytes into a fixed buffer with no NUL terminator, subsequent strlen-based parsing over-reads static memory that is then appended to outbound CoAP requests. It affects Zephyr 3.0.0 through 4.4.0 on the default-on CONFIG_LWM2M_FIRMWARE_UPDATE_PULL_SUPPORT path; there is no CISA KEV listing, EPSS is low (0.28%), and per the SSVC framework a proof-of-concept exists.	CRITICAL	9.1	0.3%	46
CVE-2026-10673	Out-of-bounds write in the Zephyr RTOS ADIN2111/ADIN1110 Ethernet driver (versions 3.7.0-4.4.x) allows an adjacent-network attacker to corrupt up to ~14.8 KB of kernel memory by sending crafted Ethernet frames over a 10BASE-T1S or 10BASE-T1L single-pair segment. The driver's OPEN Alliance SPI frame-reassembly function copies attacker-controlled 64-byte chunks into a fixed 1524-byte static buffer without validating the write cursor against the buffer boundary, enabling writes into adjacent driver and kernel memory. SSVC indicates a proof-of-concept exists; however, EPSS is low (0.23%, 14th percentile) and CISA KEV does not list active exploitation, suggesting the flaw is known but not yet widely weaponized.	HIGH	8.8	0.2%	44
CVE-2026-13212	Control-flow hijack in the Zephyr RTOS virtio driver (versions 4.2.0 through pre-4.4.2) allows a malicious or compromised virtio backend - such as an untrusted hypervisor or an untrusted PCI/MMIO virtio device - to invoke an arbitrary function pointer inside the Zephyr guest's interrupt handler. The root cause is a missing bounds check in virtio_isr() (drivers/virtio/virtio_common.c): the 16-bit descriptor-chain head ID written by the device into the used ring is consumed directly as an index into heap-allocated recv_cbs[] and desc[] arrays, each sized exactly vq->num, enabling an out-of-bounds read that returns an attacker-shaped {function pointer, argument} pair which is then called. No public exploit or active exploitation (CISA KEV) has been identified at time of analysis, but the primitive - arbitrary code execution in interrupt context triggered entirely from the backend - is high-severity and the vendor-confirmed patch is available in Zephyr 4.4.2.	HIGH	8.8	0.2%	44
CVE-2026-12522	Stack buffer overflow in Zephyr RTOS's HL7800 cellular modem driver exposes cellular-attached embedded devices to remote stack corruption during normal LTE network attach, with no device-side privileges or user interaction required. The flaw in on_cmd_atcmdinfo_ipaddr() allows a malicious or impersonated cellular network - for example via a rogue base station - to supply a crafted +CGCONTRDP response whose address fields, whose lengths are derived from attacker-controlled delimiter positions, are copied without bounds checking into fixed 64-byte and 16-byte stack buffers in supervisor context. Outcomes range from a remotely triggerable crash to potential control-flow hijacking on targets without stack canaries; no public exploit has been identified at time of analysis, and an upstream fix commit is available from the Zephyr project.	HIGH	8.8	0.2%	44
CVE-2026-9771	Local privilege escalation in Zephyr RTOS (versions 4.0.0-4.4.1 with CONFIG_USERSPACE enabled) allows an unprivileged user-mode thread to execute arbitrary code in kernel supervisor mode by supplying forged struct device pointers with attacker-controlled API function tables to the flash_copy() system call. The syscall verifier z_vrfy_flash_copy() validated the output buffer but omitted the K_SYSCALL_DRIVER_FLASH object validation for src_dev and dst_dev that every sibling flash syscall enforces - a unique gap in the trust boundary that the kernel implementation blindly dereferences in supervisor context. No public exploit or active exploitation has been identified at time of analysis; a vendor-released patch is confirmed in commit 1b1ecdc4 and available in Zephyr 4.4.2.	HIGH	8.8	0.1%	44
CVE-2026-10848	Stack buffer over-read and stray one-byte NUL write in Zephyr RTOS's experimental OCPP 1.6 client allow a malicious or compromised OCPP central server - or an on-path attacker exploiting the commonly unencrypted ws:// transport - to crash a connected embedded device by sending a crafted WAMP RPC frame with an oversized uid or action field. The vulnerable helper extract_string_field() uses strncpy() without guaranteeing NUL-termination, causing a subsequent strchr() call to scan unbounded into adjacent stack memory; a secondary defect in extract_payload() compounds this on maximal-length frames. No active exploitation has been confirmed by CISA KEV, but SSVC classification indicates publicly available proof-of-concept code, and EPSS sits at a low 0.19% (10th percentile), consistent with a niche embedded RTOS attack surface.	HIGH	8.6	0.2%	43
CVE-2026-8718	Kernel-heap buffer overflow in Zephyr RTOS's DTLS socket layer allows a low-privileged user thread to write up to 31 bytes past an attacker-controlled heap allocation in the kernel. The root cause is that tls_opt_dtls_peer_connection_id_value_get() in subsys/net/lib/sockets/sockets_tls.c forwarded a caller-supplied optval buffer to mbedtls_ssl_get_peer_cid() without verifying the buffer was at least MBEDTLS_SSL_CID_OUT_LEN_MAX (32) bytes, while the syscall verifier in CONFIG_USERSPACE builds allocated exactly optlen bytes for the bounce buffer. No public exploit code has been identified at time of analysis, and this CVE is not listed in the CISA KEV catalog.	HIGH	8.4	0.1%	42
CVE-2026-12235	Out-of-bounds write in Zephyr RTOS's llext subsystem allows a local attacker with low privileges to corrupt supervisor-context memory by loading a crafted relocatable ELF extension on Xtensa targets. The vulnerability in llext_link_plt() (subsys/llext/llext_link.c) occurs before any extension code executes - at link time - meaning sandbox protections are bypassed entirely. Exploitation complexity is high (CVSS AC:H) due to constraints on the write value, no public exploit code or CISA KEV listing exists at time of analysis, and impact is confined to deployments using llext on Xtensa architecture.	MEDIUM	6.3	10.0%	42

CVE-2026-1678

Buffer overflow in Zephyr RTOS dns_unpack_name() function causing OOB writes. PoC available.

CRITICAL

9.4

0.1%

67

PoC No patch

CVE-2026-12233

Concurrent TLS handshakes on Zephyr RTOS devices built with CONFIG_TLS_CREDENTIALS_BACKEND_PROTECTED_STORAGE cause a deterministic kernel panic and device reset via a NULL pointer dereference in the uninitialized credential mutex wait queue. The PSA Protected Storage credential backend in all affected Zephyr builds declared its serialization mutex without proper initialization, leaving its dlist sentinels as NULL; the fault triggers only on first contention but is fully deterministic once two threads race to acquire the lock. No public exploit has been identified and the issue is not in CISA KEV, though no exploit sophistication is required beyond opening multiple simultaneous TLS connections.

MEDIUM

5.9

31.0%

60

CVE-2026-7656

Forged IPv6 Neighbor Discovery acceptance in the Zephyr RTOS network stack (all releases through v4.4.0) lets an adjacent on-link attacker inject spoofed Router Advertisement, Neighbor Solicitation, and Neighbor Advertisement messages because an operator-precedence bug in subsys/net/ip/ipv6_nbr.c silently skips every RFC 4861 sanity check whenever the (always-present) ICMPv6 code is 0. Because the bypassed checks include the Hop-Limit==255 on-link proof, even off-link/remote attackers may have forged ND packets accepted, enabling default-router/DNS/SLAAC hijacking and neighbor-cache poisoning for man-in-the-middle, redirection, and denial of service. A vendor patch exists (commit 095f064c) but there is no public exploit identified at time of analysis and the issue is not in CISA KEV.

MEDIUM

6.8

0.2%

54

PoC

CVE-2026-13214

Remote code execution and denial of service in the Zephyr RTOS OCPP 1.6 client (subsys/net/lib/ocpp) allows an attacker who controls or man-in-the-middles the central system endpoint to smash the OCPP reader thread's stack. A malicious GetConfiguration message with an over-long JSON "key" field triggers an unbounded strcpy() into a fixed 50-byte stack buffer, corrupting the reader thread's stack with attacker-chosen bytes. A vendor patch exists and no public exploit has been identified at time of analysis; CVSS is rated 9.8, though real-world reach is bounded by the OCPP-charging-station niche.

CRITICAL

9.8

0.5%

50

CVE-2026-10666

Stack out-of-bounds write in the Zephyr RTOS network IP-parsing utility (parse_ipv4() in subsys/net/ip/utils.c) lets a crafted "a.b.c.d:port" address string with an overlong post-colon suffix overflow a 17-byte stack buffer with fully attacker-controlled length and contents, affecting Zephyr 1.9.0 through 4.4.0. Any application that resolves a network-influenced address string via the standard socket API (zsock_getaddrinfo/literal resolution), DNS server-string configuration, or the eswifi Wi-Fi DNS-response path is exposed, yielding at minimum denial of service and potentially control-flow hijack. No public exploit identified at time of analysis and it is not listed in CISA KEV; SSVC records proof-of-concept maturity and EPSS is low at 0.35%.

CRITICAL

9.8

0.3%

49

CVE-2026-5067

Remote code execution and denial of service in Zephyr RTOS HTTP server (versions 3.7.0 through 4.3.0) allow unauthenticated network attackers to corrupt stack memory by sending a crafted Sec-WebSocket-Key header during WebSocket upgrade. The flaw is a CWE-170 improper NUL-termination issue where a bounded copy fails to terminate the header buffer, causing strlen() and subsequent concatenation to read and write past stack bounds. No public exploit identified at time of analysis, but the CVSS 9.8 rating and trivially reachable attack surface make this a high-priority issue for any Zephyr deployment with CONFIG_HTTP_SERVER_WEBSOCKET enabled.

CRITICAL

9.8

0.2%

49

No patch

CVE-2026-12234

Kernel heap corruption via a double-fetch race condition in Zephyr RTOS's unprivileged socket syscall verifiers allows a local low-privilege attacker to achieve kernel privilege escalation or trigger a kernel denial of service. The flaw exists in z_vrfy_zsock_sendmsg() and z_vrfy_zsock_recvmsg() within subsys/net/lib/sockets/sockets.c, where msg_iovlen is read twice from live user memory - once to size the kernel heap shadow buffer and once as the iovec copy-loop bound - enabling a cooperating attacker thread to inflate the field between those reads and drive an out-of-bounds write into adjacent kernel heap objects. No public exploit has been identified at time of analysis; an upstream patch commit is confirmed available via the Zephyr project security advisory.

HIGH

7.8

8.0%

47

CVE-2026-10672

Out-of-bounds read in the Zephyr RTOS LwM2M firmware-update pull client (lwm2m_pull_context.c) lets a malicious or compromised LwM2M management server - or an on-path attacker on a session without strong DTLS - leak adjacent device memory and crash devices by writing an over-long firmware Package URI (/5/0/1). Because the Firmware-Update object stores the URI in a 255-byte buffer but the pull context copies exactly 128 bytes into a fixed buffer with no NUL terminator, subsequent strlen-based parsing over-reads static memory that is then appended to outbound CoAP requests. It affects Zephyr 3.0.0 through 4.4.0 on the default-on CONFIG_LWM2M_FIRMWARE_UPDATE_PULL_SUPPORT path; there is no CISA KEV listing, EPSS is low (0.28%), and per the SSVC framework a proof-of-concept exists.

CRITICAL

9.1

0.3%

46

CVE-2026-10673

Out-of-bounds write in the Zephyr RTOS ADIN2111/ADIN1110 Ethernet driver (versions 3.7.0-4.4.x) allows an adjacent-network attacker to corrupt up to ~14.8 KB of kernel memory by sending crafted Ethernet frames over a 10BASE-T1S or 10BASE-T1L single-pair segment. The driver's OPEN Alliance SPI frame-reassembly function copies attacker-controlled 64-byte chunks into a fixed 1524-byte static buffer without validating the write cursor against the buffer boundary, enabling writes into adjacent driver and kernel memory. SSVC indicates a proof-of-concept exists; however, EPSS is low (0.23%, 14th percentile) and CISA KEV does not list active exploitation, suggesting the flaw is known but not yet widely weaponized.

HIGH

8.8

0.2%

44

CVE-2026-13212

Control-flow hijack in the Zephyr RTOS virtio driver (versions 4.2.0 through pre-4.4.2) allows a malicious or compromised virtio backend - such as an untrusted hypervisor or an untrusted PCI/MMIO virtio device - to invoke an arbitrary function pointer inside the Zephyr guest's interrupt handler. The root cause is a missing bounds check in virtio_isr() (drivers/virtio/virtio_common.c): the 16-bit descriptor-chain head ID written by the device into the used ring is consumed directly as an index into heap-allocated recv_cbs[] and desc[] arrays, each sized exactly vq->num, enabling an out-of-bounds read that returns an attacker-shaped {function pointer, argument} pair which is then called. No public exploit or active exploitation (CISA KEV) has been identified at time of analysis, but the primitive - arbitrary code execution in interrupt context triggered entirely from the backend - is high-severity and the vendor-confirmed patch is available in Zephyr 4.4.2.

HIGH

8.8

0.2%

44

CVE-2026-12522

Stack buffer overflow in Zephyr RTOS's HL7800 cellular modem driver exposes cellular-attached embedded devices to remote stack corruption during normal LTE network attach, with no device-side privileges or user interaction required. The flaw in on_cmd_atcmdinfo_ipaddr() allows a malicious or impersonated cellular network - for example via a rogue base station - to supply a crafted +CGCONTRDP response whose address fields, whose lengths are derived from attacker-controlled delimiter positions, are copied without bounds checking into fixed 64-byte and 16-byte stack buffers in supervisor context. Outcomes range from a remotely triggerable crash to potential control-flow hijacking on targets without stack canaries; no public exploit has been identified at time of analysis, and an upstream fix commit is available from the Zephyr project.

HIGH

8.8

0.2%

44

CVE-2026-9771

Local privilege escalation in Zephyr RTOS (versions 4.0.0-4.4.1 with CONFIG_USERSPACE enabled) allows an unprivileged user-mode thread to execute arbitrary code in kernel supervisor mode by supplying forged struct device pointers with attacker-controlled API function tables to the flash_copy() system call. The syscall verifier z_vrfy_flash_copy() validated the output buffer but omitted the K_SYSCALL_DRIVER_FLASH object validation for src_dev and dst_dev that every sibling flash syscall enforces - a unique gap in the trust boundary that the kernel implementation blindly dereferences in supervisor context. No public exploit or active exploitation has been identified at time of analysis; a vendor-released patch is confirmed in commit 1b1ecdc4 and available in Zephyr 4.4.2.

HIGH

8.8

0.1%

44

CVE-2026-10848

Stack buffer over-read and stray one-byte NUL write in Zephyr RTOS's experimental OCPP 1.6 client allow a malicious or compromised OCPP central server - or an on-path attacker exploiting the commonly unencrypted ws:// transport - to crash a connected embedded device by sending a crafted WAMP RPC frame with an oversized uid or action field. The vulnerable helper extract_string_field() uses strncpy() without guaranteeing NUL-termination, causing a subsequent strchr() call to scan unbounded into adjacent stack memory; a secondary defect in extract_payload() compounds this on maximal-length frames. No active exploitation has been confirmed by CISA KEV, but SSVC classification indicates publicly available proof-of-concept code, and EPSS sits at a low 0.19% (10th percentile), consistent with a niche embedded RTOS attack surface.

HIGH

8.6

0.2%

43

CVE-2026-8718

Kernel-heap buffer overflow in Zephyr RTOS's DTLS socket layer allows a low-privileged user thread to write up to 31 bytes past an attacker-controlled heap allocation in the kernel. The root cause is that tls_opt_dtls_peer_connection_id_value_get() in subsys/net/lib/sockets/sockets_tls.c forwarded a caller-supplied optval buffer to mbedtls_ssl_get_peer_cid() without verifying the buffer was at least MBEDTLS_SSL_CID_OUT_LEN_MAX (32) bytes, while the syscall verifier in CONFIG_USERSPACE builds allocated exactly optlen bytes for the bounce buffer. No public exploit code has been identified at time of analysis, and this CVE is not listed in the CISA KEV catalog.

HIGH

8.4

0.1%

42

CVE-2026-12235

Out-of-bounds write in Zephyr RTOS's llext subsystem allows a local attacker with low privileges to corrupt supervisor-context memory by loading a crafted relocatable ELF extension on Xtensa targets. The vulnerability in llext_link_plt() (subsys/llext/llext_link.c) occurs before any extension code executes - at link time - meaning sandbox protections are bypassed entirely. Exploitation complexity is high (CVSS AC:H) due to constraints on the write value, no public exploit code or CISA KEV listing exists at time of analysis, and impact is confined to deployments using llext on Xtensa architecture.

MEDIUM

6.3

10.0%

42

Severity Breakdown

Monthly CVE Trend

Affected Products (7)

Top Risky CVEs