CVE-2026-98402 — net: icmp: avoid invalid transport header access in icmp_send tracepoint
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- No scoring signals.
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
≥ 524c341cb16a8d5318d2ffacf6fe160271a18743 and < ec6d4612d1c170e1cef1fe55526471da1e81e777≥ 21b28f97e621cba196fb32c576734d216a8a79c9 and < 99654b651c6d5fe865798a2adb859767905f9278≥ db3efdcf70c752e8a8deb16071d8e693c3ef8746 and < b972b5e6168dc5d1e13297b1f37f71d6b21cc0f1≥ db3efdcf70c752e8a8deb16071d8e693c3ef8746 and < 04c0d35bac5122b533672a6775851dfae84e265e≥ db3efdcf70c752e8a8deb16071d8e693c3ef8746 and < 2b32f8c3560905582fb12ed68315a6e606367a6a≥ db3efdcf70c752e8a8deb16071d8e693c3ef8746 and < 7fcc2fe39fed1cb98a7374a113ff3800e8f9af80≥ 6.1.130 and < 6.1.189≥ 6.6.81 and < 6.6.158 and 1 moreversion 6.10 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 14, 2026 – Oct 14, 2026
- 1× Official description updated · Oct 14, 2026 – Oct 14, 2026
References
6 on the record
- git.kernel.org/stable/c/04c0d35bac5122b533672a6775851dfae84e265e
- git.kernel.org/stable/c/7fcc2fe39fed1cb98a7374a113ff3800e8f9af80
- git.kernel.org/stable/c/b972b5e6168dc5d1e13297b1f37f71d6b21cc0f1
- git.kernel.org/stable/c/99654b651c6d5fe865798a2adb859767905f9278
- git.kernel.org/stable/c/2b32f8c3560905582fb12ed68315a6e606367a6a
- git.kernel.org/stable/c/ec6d4612d1c170e1cef1fe55526471da1e81e777
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 11h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 11h
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No FIRST EPSS score.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-98402 is "net: icmp: avoid invalid transport header access in icmp_send tracepoint", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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