CVE-2026-46266Network attack vector

Route-cache manipulation via crafted ICMP errors

Published Jun 3, 2026 · Updated Jun 3, 2026

Improper ICMP handling in the Linux kernel allows remote attackers to alter route-cache state through crafted IPv4 or IPv6 errors. The icmp_socket_deliver and icmpv6_notify paths wrongly pass protocol-255 errors to raw-socket processing instead of dropping them. This requires an IPPROTO_RAW socket on the target; the resulting FNHE changes can disrupt subsequent network traffic.

CVSS severity9.1
Critical
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper ICMP handling in the Linux kernel allows remote attackers to alter route-cache state through crafted IPv4 or IPv6 errors. The icmp_socket_deliver and icmpv6_notify paths wrongly pass protocol-255 errors to raw-socket processing instead of dropping them. This requires an IPPROTO_RAW socket on the target; the resulting FNHE changes can disrupt subsequent network traffic.

The record

CVE
CVE-2026-46266
Published
Jun 3, 2026
Updated
Jun 3, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <19e42490c89bac9a388f28179e66bebbef350f99
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <531c1aec81bfe19d00af13da5531fbb8209e4bd2
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <719d3932b8f6e3348ce2f0ac58e278301fc17575
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c89477ad79446867394360b29bb801010fc3ff22
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <db76b75ede3810e7cf9cfea5067d4f3e0993768b
  6. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <19e42490c89bac9a388f28179e66bebbef350f99; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <531c1aec81bfe19d00af13da5531fbb8209e4bd2; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <719d3932b8f6e3348ce2f0ac58e278301fc17575; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c89477ad79446867394360b29bb801010fc3ff22; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <db76b75ede3810e7cf9cfea5067d4f3e0993768b; version=2.6.12

Published CVSS scores

9.1Linux Kernel CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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