CVE-2026-46027Network attack vector

Remote kernel crash via premature link-group access

Published May 27, 2026 · Updated May 27, 2026

NULL pointer dereference in the SMC CLC handshake in Linux Kernel allows remote attackers to crash the kernel via a crafted DECLINE message. The smc_clc_wait_msg() path handles a first-contact decline before link-group setup, then writes sync_err through the unavailable lgr pointer. An unauthenticated network peer can trigger a kernel oops or panic only when an AF_SMC socket processes the malicious initial handshake.

CVSS severity7.5
High
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in the SMC CLC handshake in Linux Kernel allows remote attackers to crash the kernel via a crafted DECLINE message. The smc_clc_wait_msg() path handles a first-contact decline before link-group setup, then writes sync_err through the unavailable lgr pointer. An unauthenticated network peer can trigger a kernel oops or panic only when an AF_SMC socket processes the malicious initial handshake.

The record

CVE
CVE-2026-46027
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 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=0cfdd8f92cac01afbb12e4500514036a2b78756b <5a8db80f721deee8e916c2cfdee78decda02ce4f
  2. Affected versionversion=0cfdd8f92cac01afbb12e4500514036a2b78756b <6180a296ca65b08a81914805cbc0f78da5f10a1f
  3. Affected versionversion=0cfdd8f92cac01afbb12e4500514036a2b78756b <83bcf9228b0501694fb2589ed1d142855a2887f2
  4. Affected versionversion=0cfdd8f92cac01afbb12e4500514036a2b78756b <ea0b5d0fe96356dce38f98375a57c52a04e13712
  5. Affected versionversion=0cfdd8f92cac01afbb12e4500514036a2b78756b <f0858e1d5624bb120b198f2a8528f97a9b0ae069
  6. Affected versionversion=4.11

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0cfdd8f92cac01afbb12e4500514036a2b78756b <5a8db80f721deee8e916c2cfdee78decda02ce4f; version=0cfdd8f92cac01afbb12e4500514036a2b78756b <6180a296ca65b08a81914805cbc0f78da5f10a1f; version=0cfdd8f92cac01afbb12e4500514036a2b78756b <83bcf9228b0501694fb2589ed1d142855a2887f2; version=0cfdd8f92cac01afbb12e4500514036a2b78756b <ea0b5d0fe96356dce38f98375a57c52a04e13712; version=0cfdd8f92cac01afbb12e4500514036a2b78756b <f0858e1d5624bb120b198f2a8528f97a9b0ae069; version=4.11

Published CVSS scores

7.5LinuxCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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

T1499.004Endpoint Denial of Service: Application or System Exploitation

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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