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CVE-2026-14696— Ethernet bridge RX packet leak enables denial of service via RX buffer-pool exhaustion

Quick assessment

Affected
zephyrproject zephyr
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

当启用以太网桥接（ ）时， 中的 负责决定如何处理从桥成员接口接收到的每一帧。对于需要同时交付给本地协议栈的帧，代码会调用 并返回 。然而，该辅助函数并不会消费该数据包——它仅通过 调用 ，而该函数返回 ，且并未获取 的所有权。 随后， 判定结果会通过 传播至 中的 。在该处， 被解释为“数据包已被消费，无需释放”。但由于实际上没有消费者获取了该数据包的所有权，接收端（RX）的 永远不会被归还到池中，从而发生内存泄漏。 具体可复现的泄漏场景发生在：当 被设置（在启用 时默认为 y）时，携带未注册 L3 处理器的 E

CVSS 6.5 · Medium

Affected Version Matrix 1

VendorProduct Version RangeStatus
zephyrproject zephyr 4.4.0< 4.4.2 affected
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I. Basic Information for CVE-2026-14696

Vulnerability Information
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Vulnerability Title
Ethernet bridge RX packet leak enables denial of service via RX buffer-pool exhaustion
Source: CVE Program / CVE List V5
Vulnerability Description
When Ethernet bridging is enabled (CONFIG_NET_ETHERNET_BRIDGE), eth_bridge_input_process() in subsys/net/l2/ethernet/bridge/bridge_input.c decides how each frame received on a bridge member interface is handled. For frames that must also be delivered to the local stack, the code called eth_bridge_handle_locally() and returned NET_OK. That helper does not consume the packet — it only calls bridge_iface_recv() (via virtual_recv()), which returns NET_CONTINUE without taking ownership of pkt. The NET_OK verdict then propagates through ethernet_recv() up to processing_data() in subsys/net/ip/net_core.c, where NET_OK is interpreted as "the packet was consumed, do not free it." Because no consumer actually took ownership, the RX net_pkt is never returned to the pool and is leaked. The concretely reproducible leak occurs for frames whose EtherType has no registered L3 handler when CONFIG_NET_ETHERNET_FORWARD_UNRECOGNISED_ETHERTYPE is set (default y when CONFIG_NET_SOCKETS_PACKET is enabled): the fall-through L3 dispatch does not overwrite the NET_OK verdict, so ethernet_recv() returns NET_OK and the buffer is never released. Any device on a bridged L2 segment can emit broadcast/multicast frames carrying an arbitrary EtherType with no authentication. Each such frame permanently consumes one buffer from the finite RX pool (CONFIG_NET_PKT_RX_COUNT), so a brief broadcast flood exhausts the pool and the device can no longer receive traffic until it is rebooted — a persistent denial of service. There is no confidentiality or integrity impact. The fix makes eth_bridge_handle_locally() propagate the real net_verdict and return NET_CONTINUE for locally-kept frames, writing the bridge interface back through a new dst_iface out-parameter so the packet follows the normal receive path and is unreferenced exactly once.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
在移除最后引用时对内存的释放不恰当(内存泄露)
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
zephyrproject zephyr 4.4.0 ~ 4.4.2 -

II. Public POCs for CVE-2026-14696

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III. Intelligence Information for CVE-2026-14696

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Patches & Fixes for CVE-2026-14696 (1)

Vendor Advisories for CVE-2026-14696 (1)

Same Patch Batch · zephyrproject · 2026-08-31 · 5 CVEs total

CVE-2026-14697 6.5 MEDIUM IPv6 Neighbor Solicitation packet leak causes TX pool exhaustion denial of service
CVE-2026-14366 6.4 MEDIUM SiWx91x WiFi driver double-unref / use-after-free of caller-owned TX net_pkt
CVE-2026-14368 5.4 MEDIUM Off-by-one out-of-bounds NUL write in Zephyr LwM2M JSON string parser
CVE-2026-14367 3.1 LOW I3C IBI work-node free-list data race between ISR and workqueue thread

IV. Related Vulnerabilities

Same product: zephyr
Same vendor: zephyrproject
Same weakness: CWE-401

V. Comments for CVE-2026-14696

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