# CVE-2026-98402: net: icmp: avoid invalid transport header access in icmp_send tracepoint CVE-2026-98402 is fixed in 38 products on 1 platform, first by DEBIAN-CVE-2026-98402, released October 16, 2026. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-98402 - Priority: Routine - CVSS: 3.7 (Low) - EPSS: 0.0021 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Oct 12, 2026 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-98402 ## Description In the Linux kernel, the following vulnerability has been resolved: net: icmp: avoid invalid transport header access in icmp_send tracepoint syzbot reported a WARNING triggered by DEBUG_NET_WARN_ON_ONCE(): WARNING: at skb_transport_header include/linux/skbuff.h:3087 [inline] WARNING: at udp_hdr include/linux/udp.h:23 [inline] WARNING: at do_trace_event_raw_event_icmp_send include/trace/events/icmp.h:30 [inline] WARNING: at trace_event_raw_event_icmp_send+0x48c/0x6ec include/trace/events/icmp.h:11 Call trace: skb_transport_header include/linux/skbuff.h:3087 [inline] udp_hdr include/linux/udp.h:23 [inline] do_trace_event_raw_event_icmp_send include/trace/events/icmp.h:30 [inline] trace_event_raw_event_icmp_send+0x48c/0x6ec include/trace/events/icmp.h:11 __traceiter_icmp_send include/trace/events/icmp.h:11 [inline] __do_trace_icmp_send include/trace/events/icmp.h:11 [inline] trace_icmp_send+0x320/0x49c include/trace/events/icmp.h:11 __icmp_send+0xcfc/0x11d8 net/ipv4/icmp.c:1013 ipv4_send_dest_unreach net/ipv4/route.c:1280 [inline] ipv4_link_failure+0x57c/0x8dc net/ipv4/route.c:1287 dst_link_failure include/net/dst.h:438 [inline] vti_tunnel_xmit+0xe40/0x17a4 net/ipv4/ip_vti.c:307 TP_fast_assign() unconditionally calls udp_hdr(skb) before checking whether the packet is UDP. Furthermore, __icmp_send() can be invoked from paths (e.g., link failures, ARP errors, forwarding, AF_PACKET) where skb->transport_header was never initialized (~0U). Under CONFIG_DEBUG_NET=y, calling skb_transport_header(skb) triggers DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb)). Fix this by: 1. Only parsing transport info when iph->protocol == IPPROTO_UDP. 2. Using skb_header_pointer() at skb_network_offset(skb) + (iph->ihl << 2) to safely fetch the UDP header without assuming transport_header is set. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool6.12 amzn 2023 | 1:6.12.111-136.204.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | bpftool6.12-debuginfo amzn 2023 | 1:6.12.111-136.204.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | bpftool6.18 amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | kernel-livepatch-6.12.111-136.204 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | kernel-livepatch-6.18.54-121.166 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | kernel6.12 amzn 2023 | 1:6.12.111-136.204.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | kernel6.12-debuginfo amzn 2023 | 1:6.12.111-136.204.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | kernel6.12-debuginfo-common-aarch64 amzn 2023 | 1:6.12.111-136.204.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | kernel6.12-debuginfo-common-x86_64 amzn 2023 | 1:6.12.111-136.204.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | kernel6.12-devel amzn 2023 | 1:6.12.111-136.204.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | kernel6.12-headers amzn 2023 | 1:6.12.111-136.204.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | kernel6.12-modules-extra amzn 2023 | 1:6.12.111-136.204.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | kernel6.12-modules-extra-common amzn 2023 | 1:6.12.111-136.204.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | kernel6.12-tools amzn 2023 | 1:6.12.111-136.204.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | kernel6.12-tools-debuginfo amzn 2023 | 1:6.12.111-136.204.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | kernel6.12-tools-devel amzn 2023 | 1:6.12.111-136.204.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | kernel6.18 amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | kernel6.18-devel amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | kernel6.18-headers amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | kernel6.18-tools amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | linux Debian 12.15 (bookworm) | 6.1.190-1 | [DEBIAN-CVE-2026-98402](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98402.md) | Oct 16, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.111-1 | [DEBIAN-CVE-2026-98402](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98402.md) | Oct 16, 2026 | | Linux | linux Debian 14 | 7.2.7-1 | [DEBIAN-CVE-2026-98402](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98402.md) | Oct 16, 2026 | | Linux | microvm-kernel6.18 amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | perf6.12 amzn 2023 | 1:6.12.111-136.204.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | perf6.12-debuginfo amzn 2023 | 1:6.12.111-136.204.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | perf6.18 amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | python3-perf6.12 amzn 2023 | 1:6.12.111-136.204.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | python3-perf6.12-debuginfo amzn 2023 | 1:6.12.111-136.204.amzn2023 | [ALAS2023-2026-3193](https://patchblox.com/security/data/fix/linux/alas2023-2026-3193.md) | Nov 7, 2026 | | Linux | python3-perf6.18 amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | | Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 | --- Data as of 2026-11-08T13:06:02Z UTC. 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