CVE-2026-98402
Status: ReceivedUnscored—
Severity—Unscored
Exploitation probability0.21 %higher than 11% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitNot knownno public code found
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():
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.
Technical details traces, logs and code from the original report
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
CVSS
NVD hasn't assigned a CVSS score to this CVE (common since the April 2026 policy change).
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days
- 0.21 %
- Percentile among all scored CVEs
- 11
- Score date
- 10/21/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
Affected technologies (1)
⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.
References
Show 6 references
- https://git.kernel.org/stable/c/04c0d35bac5122b533672a6775851dfae84e265e
- https://git.kernel.org/stable/c/2b32f8c3560905582fb12ed68315a6e606367a6a
- https://git.kernel.org/stable/c/7fcc2fe39fed1cb98a7374a113ff3800e8f9af80
- https://git.kernel.org/stable/c/99654b651c6d5fe865798a2adb859767905f9278
- https://git.kernel.org/stable/c/b972b5e6168dc5d1e13297b1f37f71d6b21cc0f1
- https://git.kernel.org/stable/c/ec6d4612d1c170e1cef1fe55526471da1e81e777
Raw JSON (NVD)
Show
{
"id": "CVE-2026-98402",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "524c341cb16a8d5318d2ffacf6fe160271a18743",
"lessThan": "ec6d4612d1c170e1cef1fe55526471da1e81e777",
"versionType": "git"
},
{
"status": "affected",
"version": "21b28f97e621cba196fb32c576734d216a8a79c9",
"lessThan": "99654b651c6d5fe865798a2adb859767905f9278",
"versionType": "git"
},
{
"status": "affected",
"version": "db3efdcf70c752e8a8deb16071d8e693c3ef8746",
"lessThan": "b972b5e6168dc5d1e13297b1f37f71d6b21cc0f1",
"versionType": "git"
},
{
"status": "affected",
"version": "db3efdcf70c752e8a8deb16071d8e693c3ef8746",
"lessThan": "04c0d35bac5122b533672a6775851dfae84e265e",
"versionType": "git"
},
{
"status": "affected",
"version": "db3efdcf70c752e8a8deb16071d8e693c3ef8746",
"lessThan": "2b32f8c3560905582fb12ed68315a6e606367a6a",
"versionType": "git"
},
{
"status": "affected",
"version": "db3efdcf70c752e8a8deb16071d8e693c3ef8746",
"lessThan": "7fcc2fe39fed1cb98a7374a113ff3800e8f9af80",
"versionType": "git"
},
{
"status": "affected",
"version": "6.1.130",
"lessThan": "6.1.189",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.6.81",
"lessThan": "6.6.158",
"versionType": "semver"
}
],
"programFiles": [
"include/trace/events/icmp.h"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.10"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.10",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.189",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.7",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/trace/events/icmp.h"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-10-14T14:17:51.257",
"references": [
{
"url": "https://git.kernel.org/stable/c/04c0d35bac5122b533672a6775851dfae84e265e",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/2b32f8c3560905582fb12ed68315a6e606367a6a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/7fcc2fe39fed1cb98a7374a113ff3800e8f9af80",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/99654b651c6d5fe865798a2adb859767905f9278",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/b972b5e6168dc5d1e13297b1f37f71d6b21cc0f1",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ec6d4612d1c170e1cef1fe55526471da1e81e777",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "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_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."
}
],
"lastModified": "2026-10-19T10:18:45.083",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}