{"id":"CVE-2026-10639","aliases":["EUVD-2026-37116","GHSA-qhrf-w466-qmpw"],"status":"published","title":"Use-after-free reading `net_pkt_iface()` of a sent ICMPv4 echo-reply packet in `icmpv4_handle_echo_request()`","description":"In Zephyr's native IPv4 stack, icmpv4_handle_echo_request() in subsys/net/ip/icmpv4.c builds an echo-reply packet (reply), hands it to net_try_send_data(), and then, on success, calls net_stats_update_icmp_sent(net_pkt_iface(reply)). net_try_send_data() transfers ownership of reply to the TX path (net_if_try_queue_tx -\u003e net_if_tx -\u003e L2/driver send, or the asynchronous net_if_tx_thread), which can unref it to refcount 0 and return the struct net_pkt to its slab (net_pkt_unref -\u003e k_mem_slab_free) before the stats line runs. net_core.c documents this exact contract ('the pkt might contain garbage already ... do not use pkt after that call').\n\nThe post-send net_pkt_iface(reply) therefore reads reply-\u003eiface out of a freed (and possibly already reallocated) net_pkt, a use-after-free read; with CONFIG_NET_STATISTICS_PER_INTERFACE the stats macro additionally increments a counter through that value, i.e. a dereference/write through a stale or recycled-slot pointer.\n\nThe path is reached unauthenticated by any remote host that pings the device (net_icmpv4_input -\u003e net_icmp_call_ipv4_handlers -\u003e icmpv4_handle_echo_request) and is gated on CONFIG_NET_STATISTICS_ICMP. Impact is a probabilistic read of recycled packet memory plus a possible wild-pointer write under a timing race, leading most likely to corrupted interface statistics or a remotely triggerable crash (DoS).\n\nThe defect was introduced in 2019 (v1.14) and is present through v4.4.0. The companion change in net_icmpv4_send_error() is not a use-after-free because it reads net_pkt_iface(orig), the caller-owned received packet, which stays alive across the send. The fix caches the interface pointer from the live received packet before sending and uses it for the post-send stats updates.","severity":{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00232,"percentile":0.14219,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-416"],"published":"2026-06-16T13:22:23Z","modified":"2026-11-04T04:58:09Z","products":[{"vendor":"zephyrproject","product":"zephyr"},{"vendor":"zephyrproject-rtos","product":"zephyr"}],"references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/commit/86e21665d4641f304dc3895bfb03b8f89db83291","tags":["patch","Patch","fix"]},{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-qhrf-w466-qmpw","tags":["Exploit","Patch","Vendor Advisory","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/10xxx/CVE-2026-10639.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-10639","tags":["advisory"]},{"url":"https://github.com/zephyrproject-rtos/zephyr","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-10639","title":"Use-after-free reading `net_pkt_iface()` of a sent ICMPv4 echo-reply packet in `icmpv4_handle_echo_request()`","description":"In Zephyr's native IPv4 stack, icmpv4_handle_echo_request() in subsys/net/ip/icmpv4.c builds an echo-reply packet (reply), hands it to net_try_send_data(), and then, on success, calls net_stats_update_icmp_sent(net_pkt_iface(reply)). net_try_send_data() transfers ownership of reply to the TX path (net_if_try_queue_tx -\u003e net_if_tx -\u003e L2/driver send, or the asynchronous net_if_tx_thread), which can unref it to refcount 0 and return the struct net_pkt to its slab (net_pkt_unref -\u003e k_mem_slab_free) before the stats line runs. net_core.c documents this exact contract ('the pkt might contain garbage already ... do not use pkt after that call').\n\nThe post-send net_pkt_iface(reply) therefore reads reply-\u003eiface out of a freed (and possibly already reallocated) net_pkt, a use-after-free read; with CONFIG_NET_STATISTICS_PER_INTERFACE the stats macro additionally increments a counter through that value, i.e. a dereference/write through a stale or recycled-slot pointer.\n\nThe path is reached unauthenticated by any remote host that pings the device (net_icmpv4_input -\u003e net_icmp_call_ipv4_handlers -\u003e icmpv4_handle_echo_request) and is gated on CONFIG_NET_STATISTICS_ICMP. Impact is a probabilistic read of recycled packet memory plus a possible wild-pointer write under a timing race, leading most likely to corrupted interface statistics or a remotely triggerable crash (DoS).\n\nThe defect was introduced in 2019 (v1.14) and is present through v4.4.0. The companion change in net_icmpv4_send_error() is not a use-after-free because it reads net_pkt_iface(orig), the caller-owned received packet, which stays alive across the send. The fix caches the interface pointer from the live received packet before sending and uses it for the post-send stats updates.","status":"published","published":"2026-06-16T13:22:23.165Z","modified":"2026-11-04T04:58:09.872Z","cvss":[{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-416"],"updated_at":"2026-11-04T05:21:48.223566Z"}],"euvd":[{"id":"EUVD-2026-37116","description":"In Zephyr's native IPv4 stack, icmpv4_handle_echo_request() in subsys/net/ip/icmpv4.c builds an echo-reply packet (reply), hands it to net_try_send_data(), and then, on success, calls net_stats_update_icmp_sent(net_pkt_iface(reply)). net_try_send_data() transfers ownership of reply to the TX path (net_if_try_queue_tx -\u003e net_if_tx -\u003e L2/driver send, or the asynchronous net_if_tx_thread), which can unref it to refcount 0 and return the struct net_pkt to its slab (net_pkt_unref -\u003e k_mem_slab_free) before the stats line runs. net_core.c documents this exact contract ('the pkt might contain garbage already ... do not use pkt after that call').\n\nThe post-send net_pkt_iface(reply) therefore reads reply-\u003eiface out of a freed (and possibly already reallocated) net_pkt, a use-after-free read; with CONFIG_NET_STATISTICS_PER_INTERFACE the stats macro additionally increments a counter through that value, i.e. a dereference/write through a stale or recycled-slot pointer.\n\nThe path is reached unauthenticated by any remote host that pings the device (net_icmpv4_input -\u003e net_icmp_call_ipv4_handlers -\u003e icmpv4_handle_echo_request) and is gated on CONFIG_NET_STATISTICS_ICMP. Impact is a probabilistic read of recycled packet memory plus a possible wild-pointer write under a timing race, leading most likely to corrupted interface statistics or a remotely triggerable crash (DoS).\n\nThe defect was introduced in 2019 (v1.14) and is present through v4.4.0. The companion change in net_icmpv4_send_error() is not a use-after-free because it reads net_pkt_iface(orig), the caller-owned received packet, which stays alive across the send. The fix caches the interface pointer from the live received packet before sending and uses it for the post-send stats updates.","status":"published","published":"2026-06-16T13:22:23Z","modified":"2026-11-04T04:58:09Z","cvss":[{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium"}],"updated_at":"2026-11-04T07:00:57.274021Z"}],"nvd":[{"id":"CVE-2026-10639","description":"In Zephyr's native IPv4 stack, icmpv4_handle_echo_request() in subsys/net/ip/icmpv4.c builds an echo-reply packet (reply), hands it to net_try_send_data(), and then, on success, calls net_stats_update_icmp_sent(net_pkt_iface(reply)). net_try_send_data() transfers ownership of reply to the TX path (net_if_try_queue_tx -\u003e net_if_tx -\u003e L2/driver send, or the asynchronous net_if_tx_thread), which can unref it to refcount 0 and return the struct net_pkt to its slab (net_pkt_unref -\u003e k_mem_slab_free) before the stats line runs. net_core.c documents this exact contract ('the pkt might contain garbage already ... do not use pkt after that call').\n\nThe post-send net_pkt_iface(reply) therefore reads reply-\u003eiface out of a freed (and possibly already reallocated) net_pkt, a use-after-free read; with CONFIG_NET_STATISTICS_PER_INTERFACE the stats macro additionally increments a counter through that value, i.e. a dereference/write through a stale or recycled-slot pointer.\n\nThe path is reached unauthenticated by any remote host that pings the device (net_icmpv4_input -\u003e net_icmp_call_ipv4_handlers -\u003e icmpv4_handle_echo_request) and is gated on CONFIG_NET_STATISTICS_ICMP. Impact is a probabilistic read of recycled packet memory plus a possible wild-pointer write under a timing race, leading most likely to corrupted interface statistics or a remotely triggerable crash (DoS).\n\nThe defect was introduced in 2019 (v1.14) and is present through v4.4.0. The companion change in net_icmpv4_send_error() is not a use-after-free because it reads net_pkt_iface(orig), the caller-owned received packet, which stays alive across the send. The fix caches the interface pointer from the live received packet before sending and uses it for the post-send stats updates.","status":"published","published":"2026-06-16T15:16:34.207Z","modified":"2026-10-25T23:10:00.167Z","cvss":[{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium","assessor":"secondary"},{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium","assessor":"primary"}],"cwes":["CWE-416"],"updated_at":"2026-11-02T14:12:24.19758Z"}],"osv":[{"id":"CVE-2026-10639","title":"Use-after-free reading `net_pkt_iface()` of a sent ICMPv4 echo-reply packet in `icmpv4_handle_echo_request()`","description":"In Zephyr's native IPv4 stack, icmpv4_handle_echo_request() in subsys/net/ip/icmpv4.c builds an echo-reply packet (reply), hands it to net_try_send_data(), and then, on success, calls net_stats_update_icmp_sent(net_pkt_iface(reply)). net_try_send_data() transfers ownership of reply to the TX path (net_if_try_queue_tx -\u003e net_if_tx -\u003e L2/driver send, or the asynchronous net_if_tx_thread), which can unref it to refcount 0 and return the struct net_pkt to its slab (net_pkt_unref -\u003e k_mem_slab_free) before the stats line runs. net_core.c documents this exact contract ('the pkt might contain garbage already ... do not use pkt after that call').\n\nThe post-send net_pkt_iface(reply) therefore reads reply-\u003eiface out of a freed (and possibly already reallocated) net_pkt, a use-after-free read; with CONFIG_NET_STATISTICS_PER_INTERFACE the stats macro additionally increments a counter through that value, i.e. a dereference/write through a stale or recycled-slot pointer.\n\nThe path is reached unauthenticated by any remote host that pings the device (net_icmpv4_input -\u003e net_icmp_call_ipv4_handlers -\u003e icmpv4_handle_echo_request) and is gated on CONFIG_NET_STATISTICS_ICMP. Impact is a probabilistic read of recycled packet memory plus a possible wild-pointer write under a timing race, leading most likely to corrupted interface statistics or a remotely triggerable crash (DoS).\n\nThe defect was introduced in 2019 (v1.14) and is present through v4.4.0. The companion change in net_icmpv4_send_error() is not a use-after-free because it reads net_pkt_iface(orig), the caller-owned received packet, which stays alive across the send. The fix caches the interface pointer from the live received packet before sending and uses it for the post-send stats updates.","status":"published","published":"2026-06-16T13:22:23.165Z","modified":"2026-11-05T08:04:00.483775164Z","cvss":[{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium"}],"cwes":["CWE-416"],"updated_at":"2026-11-05T09:08:14.330889Z"}]}}