{"id":"CVE-2026-10640","summary":"Use-after-free reading `net_pkt` `iface` after send in IPv6 Neighbor Discovery (`ipv6_nbr.c`)","details":"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 -\u003e 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).\n\nThe subsequent net_pkt_iface(pkt) reads pkt-\u003eiface from the freed slab block, and with CONFIG_NET_STATISTICS_PER_INTERFACE enabled that loaded pointer is dereferenced to increment iface-\u003estats.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.\n\nThe 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 -\u003e net_ipv6_send_na).\n\nAffected 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.","aliases":["GHSA-r74c-mr4m-7g9g"],"modified":"2026-11-05T08:04:02.821673521Z","published":"2026-06-16T13:28:24.493Z","database_specific":{"cwe_ids":["CWE-416"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/10xxx/CVE-2026-10640.json","cna_assigner":"zephyr"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/10xxx/CVE-2026-10640.json"},{"type":"ADVISORY","url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-r74c-mr4m-7g9g"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-10640"},{"type":"FIX","url":"https://github.com/zephyrproject-rtos/zephyr/commit/aaed8332a62b0490a2f3c2cbabe272f575068eaa"},{"type":"PACKAGE","url":"https://github.com/zephyrproject-rtos/zephyr"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/zephyrproject-rtos/zephyr","events":[{"introduced":"07c6af3b8c35c1e49186578ca61a25c76e2fb308"},{"fixed":"75f67d766726351b30199f9a2bf55803d717a3be"},{"introduced":"684c9e8f32e4373a21098559f748f06915f950c9"},{"fixed":"1f6485eca25431b5ff27ce9a754218c9e559bbbb"},{"fixed":"aaed8332a62b0490a2f3c2cbabe272f575068eaa"}],"database_specific":{"extracted_events":[{"range":[{"introduced":"3.3.0"},{"fixed":"4.3.1"}],"source":"AFFECTED_FIELD","strategy":"StandardRange"},{"source":"AFFECTED_FIELD","strategy":"StandardRange","range":[{"introduced":"4.4.0"},{"fixed":"4.4.1"}]},{"range":[{"fixed":"aaed8332a62b0490a2f3c2cbabe272f575068eaa"}],"source":"REFERENCES_COMMIT"}]}}],"versions":["v4.3.1-rc1","v4.4.1-rc1","v4.4.0","v4.3.0","v4.3.0-rc3","v4.3.0-rc2","v4.3.0-rc1","v4.2.0","v4.2.0-rc3","v4.2.0-rc2","v4.2.0-rc1","v4.1.0","v4.1.0-rc3","v4.1.0-rc2","v4.1.0-rc1","v4.0.0","v4.0.0-rc3","v4.0.0-rc2","v4.0.0-rc1","v3.7.0","v3.7.0-rc3","v3.7.0-rc2","v3.7.0-rc1","v3.6.0","v3.6.0-rc3","v3.6.0-rc2","v3.6.0-rc1","zephyr-v3.5.0","v3.5.0","v3.5.0-rc3","v3.5.0-rc2","v3.5.0-rc1","zephyr-v3.4.0","v3.4.0","v3.4.0-rc3","v3.4.0-rc2","v3.4.0-rc1","zephyr-v3.3.0","v3.3.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-10640.json","vanir_signatures":[{"id":"CVE-2026-10640-16c02da8","signature_type":"Line","signature_version":"v1","source":"https://github.com/zephyrproject-rtos/zephyr/commit/aaed8332a62b0490a2f3c2cbabe272f575068eaa","target":{"file":"subsys/net/ip/ipv6_nbr.c"},"deprecated":false,"digest":{"line_hashes":["91287654074939685182679574636412394896","15227908928454866318017343628738582294","184531941854350676137052727205553850158","207883878984180498172001944300157653088","162790215008363859843239656648498494482","196893312463318997455331973915328240641","298242661318329454041778475710905117604","207883878984180498172001944300157653088","91287654074939685182679574636412394896","15227908928454866318017343628738582294","184531941854350676137052727205553850158","207883878984180498172001944300157653088"],"threshold":0.9}},{"deprecated":false,"digest":{"function_hash":"267183217340134069590489850874797830891","length":2789},"id":"CVE-2026-10640-8b218a2b","signature_type":"Function","signature_version":"v1","source":"https://github.com/zephyrproject-rtos/zephyr/commit/aaed8332a62b0490a2f3c2cbabe272f575068eaa","target":{"file":"subsys/net/ip/ipv6_nbr.c","function":"net_ipv6_send_ns"}},{"digest":{"function_hash":"52037421534442246379070261010880927722","length":975},"id":"CVE-2026-10640-b402014f","signature_type":"Function","signature_version":"v1","source":"https://github.com/zephyrproject-rtos/zephyr/commit/aaed8332a62b0490a2f3c2cbabe272f575068eaa","target":{"file":"subsys/net/ip/ipv6_nbr.c","function":"net_ipv6_send_rs"},"deprecated":false},{"deprecated":false,"digest":{"function_hash":"121515546642206997958598429868473409545","length":1217},"id":"CVE-2026-10640-bf24dde2","signature_type":"Function","signature_version":"v1","source":"https://github.com/zephyrproject-rtos/zephyr/commit/aaed8332a62b0490a2f3c2cbabe272f575068eaa","target":{"function":"net_ipv6_send_na","file":"subsys/net/ip/ipv6_nbr.c"}}],"vanir_signatures_modified":"2026-11-05T08:04:02Z"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L"}]}