{"api_version":"1","generated_at":"2026-09-15T08:41:19+00:00","cve":"CVE-2026-14696","urls":{"html":"https://cve.report/CVE-2026-14696","api":"https://cve.report/api/cve/CVE-2026-14696.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-14696","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-14696"},"summary":{"title":"Ethernet bridge RX packet leak enables denial of service via RX buffer-pool exhaustion","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.\n\nThe 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.\n\nAny 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.\n\nThe 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.","state":"PUBLISHED","assigner":"zephyr","published_at":"2026-08-31 19:16:46","updated_at":"2026-09-01 15:17:11"},"problem_types":["CWE-401","CWE-401 dos"],"metrics":[{"version":"3.1","source":"vulnerabilities@zephyrproject.org","type":"Secondary","score":"6.5","severity":"MEDIUM","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":6.5,"baseSeverity":"MEDIUM","attackVector":"ADJACENT_NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"CVSS","score":"6.5","severity":"MEDIUM","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"baseScore":6.5,"baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/4eb007af465a1d28f2f35d93ecf139cc62c542a7","name":"https://github.com/zephyrproject-rtos/zephyr/commit/4eb007af465a1d28f2f35d93ecf139cc62c542a7","refsource":"vulnerabilities@zephyrproject.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-3m4w-wc4v-766q","name":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-3m4w-wc4v-766q","refsource":"vulnerabilities@zephyrproject.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-14696","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-14696","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"zephyrproject","product":"zephyr","version":"affected 4.4.0 4.4.2 semver","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"14696","cve":"CVE-2026-14696","epss":"0.001990000","percentile":"0.097310000","score_date":"2026-09-03","updated_at":"2026-09-04 00:08:07"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"other":{"content":{"id":"CVE-2026-14696","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2026-09-01T14:00:41.960566Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-09-01T14:01:28.688Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"collectionURL":"https://github.com/zephyrproject-rtos/zephyr","defaultStatus":"unaffected","packageName":"zephyr","product":"zephyr","programFiles":["include/zephyr/net/ethernet_bridge.h","subsys/net/l2/ethernet/bridge/bridge_input.c","subsys/net/l2/ethernet/ethernet.c"],"programRoutines":[{"name":"eth_bridge_handle_locally"},{"name":"eth_bridge_input_process"},{"name":"ethernet_recv"}],"vendor":"zephyrproject","versions":[{"lessThan":"4.4.2","status":"affected","version":"4.4.0","versionType":"semver"}]}],"descriptions":[{"lang":"en","value":"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.\n\nThe 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.\n\nAny 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.\n\nThe 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."}],"metrics":[{"cvssV3_1":{"baseScore":6.5,"baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-401","description":"dos","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-08-31T18:57:06.627Z","orgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","shortName":"zephyr"},"references":[{"name":"Fix commit","tags":["patch"],"url":"https://github.com/zephyrproject-rtos/zephyr/commit/4eb007af465a1d28f2f35d93ecf139cc62c542a7"},{"name":"GHSA-3m4w-wc4v-766q","url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-3m4w-wc4v-766q"}],"title":"Ethernet bridge RX packet leak enables denial of service via RX buffer-pool exhaustion","x_generator":{"engine":"cvelib 1.8.0"}}},"cveMetadata":{"assignerOrgId":"e2e69745-5e70-4e92-8431-deb5529a81ad","assignerShortName":"zephyr","cveId":"CVE-2026-14696","datePublished":"2026-08-31T18:57:06.627Z","dateReserved":"2026-07-04T05:18:34.276Z","dateUpdated":"2026-09-01T14:01:28.688Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-31 19:16:46","lastModifiedDate":"2026-09-01 15:17:11","problem_types":["CWE-401","CWE-401 dos"],"metrics":{"cvssMetricV31":[{"source":"vulnerabilities@zephyrproject.org","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":6.5,"baseSeverity":"MEDIUM","attackVector":"ADJACENT_NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":2.8,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-09-01T14:00:41.960566Z","id":"CVE-2026-14696","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"14696","Ordinal":"1","Title":"Ethernet bridge RX packet leak enables denial of service via RX ","CVE":"CVE-2026-14696","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"14696","Ordinal":"1","NoteData":"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.\n\nThe 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.\n\nAny 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.\n\nThe 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.","Type":"Description","Title":"Ethernet bridge RX packet leak enables denial of service via RX "}]}}}