CVE-2025-38734Network attack vector

Remote kernel memory corruption via SMC socket race

Published Sep 5, 2025 · Updated Sep 5, 2025

Use-after-free in Linux kernel SMC networking allows remote attackers to corrupt kernel memory through an unauthenticated handshake. The smc_listen_work handler dereferences newclcsock->sk after smc_listen_out releases the socket when a server application accepts and immediately closes it. An unauthenticated SMC peer can repeatedly win the race, causing kernel-memory reads or writes, control-flow hijacking, or a system panic.

CVSS severity9.8
Critical
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux kernel SMC networking allows remote attackers to corrupt kernel memory through an unauthenticated handshake. The smc_listen_work handler dereferences newclcsock->sk after smc_listen_out releases the socket when a server application accepts and immediately closes it. An unauthenticated SMC peer can repeatedly win the race, causing kernel-memory reads or writes, control-flow hijacking, or a system panic.

The record

CVE
CVE-2025-38734
Published
Sep 5, 2025
Updated
Sep 5, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 5, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 5, 2025Record 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=3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8 <070b4af44c4b6e4c35fb1ca7001a6a88fd2d318f
  2. Affected versionversion=3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8 <2e765ba0ee0eae35688b443e97108308a716773e
  3. Affected versionversion=3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8 <85545f1525f9fa9bf44fec77ba011024f15da342
  4. Affected versionversion=3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8 <d9cef55ed49117bd63695446fb84b4b91815c0b4
  5. Affected versionversion=4.18

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8 <070b4af44c4b6e4c35fb1ca7001a6a88fd2d318f; version=3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8 <2e765ba0ee0eae35688b443e97108308a716773e; version=3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8 <85545f1525f9fa9bf44fec77ba011024f15da342; version=3b2dec2603d5b06ad3af71c1164ca0b92df3d2a8 <d9cef55ed49117bd63695446fb84b4b91815c0b4; version=4.18

Published CVSS scores

9.8LinuxCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.8UbuntuCVSS:3.1/AV:L/AC:L/PR:L/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

T1190Exploit Public-Facing Application

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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