{"id":"CVE-2026-98402","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: icmp: avoid invalid transport header access in icmp_send tracepoint\n\nsyzbot reported a WARNING triggered by DEBUG_NET_WARN_ON_ONCE():\n\n WARNING: at skb_transport_h…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: icmp: avoid invalid transport header access in icmp_send tracepoint\n\nsyzbot reported a WARNING triggered by DEBUG_NET_WARN_ON_ONCE():\n\n WARNING: at skb_transport_h…","severity":"medium","published":"2026-10-14","updated":"2026-10-14","sourceUpdated":"2026-10-14T14:17:51.257","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-98402","references":[{"url":"https://git.kernel.org/stable/c/04c0d35bac5122b533672a6775851dfae84e265e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2b32f8c3560905582fb12ed68315a6e606367a6a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7fcc2fe39fed1cb98a7374a113ff3800e8f9af80","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/99654b651c6d5fe865798a2adb859767905f9278","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b972b5e6168dc5d1e13297b1f37f71d6b21cc0f1","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ec6d4612d1c170e1cef1fe55526471da1e81e777","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98402.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-98402"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2552227"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98402"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98402"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98402.mbox"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"ingestedAt":"2026-10-14T15:36:13.981Z","vendor":"Linux","product":"Linux","affected":["Linux >= 524c341cb16a8d5318d2ffacf6fe160271a18743 < ec6d4612d1c170e1cef1fe55526471da1e81e777","Linux >= 21b28f97e621cba196fb32c576734d216a8a79c9 < 99654b651c6d5fe865798a2adb859767905f9278","Linux >= db3efdcf70c752e8a8deb16071d8e693c3ef8746 < b972b5e6168dc5d1e13297b1f37f71d6b21cc0f1","Linux >= db3efdcf70c752e8a8deb16071d8e693c3ef8746 < 04c0d35bac5122b533672a6775851dfae84e265e","Linux >= db3efdcf70c752e8a8deb16071d8e693c3ef8746 < 2b32f8c3560905582fb12ed68315a6e606367a6a","Linux >= db3efdcf70c752e8a8deb16071d8e693c3ef8746 < 7fcc2fe39fed1cb98a7374a113ff3800e8f9af80","Linux >= 6.1.130 < 6.1.189","Linux >= 6.6.81 < 6.6.158","Linux 6.10"],"cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":["CWE-824"],"epss":0.00211,"epssPercentile":0.11319,"slug":"CVE-2026-98402","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet: icmp: avoid invalid transport header access in icmp_send tracepoint\n\nsyzbot reported a WARNING triggered by DEBUG_NET_WARN_ON_ONCE():\n\n WARNING: at skb_transport_header include/linux/skbuff.h:3087 [inline]\n WARNING: at udp_hdr include/linux/udp.h:23 [inline]\n WARNING: at do_trace_event_raw_event_icmp_send include/trace/events/icmp.h:30 [inline]\n WARNING: at trace_event_raw_event_icmp_send+0x48c/0x6ec include/trace/events/icmp.h:11\n Call trace:\n  skb_transport_header include/linux/skbuff.h:3087 [inline]\n  udp_hdr include/linux/udp.h:23 [inline]\n  do_trace_event_raw_event_icmp_send include/trace/events/icmp.h:30 [inline]\n  trace_event_raw_event_icmp_send+0x48c/0x6ec include/trace/events/icmp.h:11\n  __traceiter_icmp_send include/trace/events/icmp.h:11 [inline]\n  __do_trace_icmp_send include/trace/events/icmp.h:11 [inline]\n  trace_icmp_send+0x320/0x49c include/trace/events/icmp.h:11\n  __icmp_send+0xcfc/0x11d8 net/ipv4/icmp.c:1013\n  ipv4_send_dest_unreach net/ipv4/route.c:1280 [inline]\n  ipv4_link_failure+0x57c/0x8dc net/ipv4/route.c:1287\n  dst_link_failure include/net/dst.h:438 [inline]\n  vti_tunnel_xmit+0xe40/0x17a4 net/ipv4/ip_vti.c:307\n\nTP_fast_assign() unconditionally calls udp_hdr(skb) before checking\nwhether the packet is UDP. Furthermore, __icmp_send() can be invoked\nfrom paths (e.g., link failures, ARP errors, forwarding, AF_PACKET)\nwhere skb->transport_header was never initialized (~0U).\n\nUnder CONFIG_DEBUG_NET=y, calling skb_transport_header(skb) triggers\nDEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb)).\n\nFix this by:\n1. Only parsing transport info when iph->protocol == IPPROTO_UDP.\n2. Using skb_header_pointer() at skb_network_offset(skb) + (iph->ihl << 2)\n   to safely fetch the UDP header without assuming transport_header is set.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10 · updated 2026-10-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98402.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":224099,"id":"CVE-2026-98402","ts":1792324919689,"field":"cvss","old":null,"new":"5.5"},{"seq":224098,"id":"CVE-2026-98402","ts":1792324919689,"field":"severity","old":"none","new":"medium"}]}