CVE-2026-43186Network attack vector

System crash via unchecked IOAM node length

Published May 6, 2026 · Updated May 6, 2026

Heap buffer overflow in the Linux Kernel IPv6 IOAM receive path allows remote attackers to trigger a kernel panic with a crafted packet. __ioam6_fill_trace_data() trusts the packet-controlled nodelen value without checking it against trace->type, permitting writes past the allocated region into adjacent heap memory. The target interface must have IPv6 IOAM enabled; no authentication or user interaction is required, and the demonstrated consequence is a system crash.

CVSS severity9.8
Critical
EPSS probability0.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap buffer overflow in the Linux Kernel IPv6 IOAM receive path allows remote attackers to trigger a kernel panic with a crafted packet. __ioam6_fill_trace_data() trusts the packet-controlled nodelen value without checking it against trace->type, permitting writes past the allocated region into adjacent heap memory. The target interface must have IPv6 IOAM enabled; no authentication or user interaction is required, and the demonstrated consequence is a system crash.

The record

CVE
CVE-2026-43186
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-787, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 6, 2026CVE publishedPublication date reported by the CVE source.
  2. May 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.15
  2. Affected versionversion=9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 <0591d6509c2ff13f09ea2998434aba0c0472e978
  3. Affected versionversion=9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 <632d233cf2e64a46865ae2c064ae3c9df7c8864f
  4. Affected versionversion=9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 <6db8b56eed62baacaf37486e83378a72635c04cc
  5. Affected versionversion=9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 <e90346a2f1e8917d5760a44a1f61c44e3b36d96b
  6. Affected versionversion=9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 <ea3632aefc04205436868541638e26f4a74d5637
  7. Affected versionversion=9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 <f4d9d4b8fd839719d564651671e24c62c545c23b
  8. Affected versionversion=9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 <fb3c662fafebc5b9d74417ed1de8759f6bb72143

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.15; version=9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 <0591d6509c2ff13f09ea2998434aba0c0472e978; version=9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 <632d233cf2e64a46865ae2c064ae3c9df7c8864f; version=9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 <6db8b56eed62baacaf37486e83378a72635c04cc; version=9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 <e90346a2f1e8917d5760a44a1f61c44e3b36d96b; version=9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 <ea3632aefc04205436868541638e26f4a74d5637; version=9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 <f4d9d4b8fd839719d564651671e24c62c545c23b; version=9ee11f0fff205b4b3df9750bff5e94f97c71b6a0 <fb3c662fafebc5b9d74417ed1de8759f6bb72143

Published CVSS scores

9.8kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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