CVE-2026-23450Public exploitNetwork attack vector

Remote kernel crash via SMC listener race

Published Apr 3, 2026 · Updated Apr 3, 2026

Use-after-free in the Linux Kernel SMC TCP receive path allows remote attackers to crash the kernel through an exposed SMC listener. The callback reads sk_user_data without RCU protection or a live smc_sock reference while concurrent close clears the pointer and frees the object. An enabled SMC listening socket and concurrent handshake traffic plus listener teardown are required; the demonstrated consequence is an oops or panic.

CVSS severity9.8
Critical
EPSS probability0.56%
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 the Linux Kernel SMC TCP receive path allows remote attackers to crash the kernel through an exposed SMC listener. The callback reads sk_user_data without RCU protection or a live smc_sock reference while concurrent close clears the pointer and frees the object. An enabled SMC listening socket and concurrent handshake traffic plus listener teardown are required; the demonstrated consequence is an oops or panic.

The record

CVE
CVE-2026-23450
Published
Apr 3, 2026
Updated
Apr 3, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 3, 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=5.18
  2. Affected versionversion=8270d9c21041470f58348248b9d9dcf3bf79592e <1e4f873879e075bbd4eb1c644d6933303ac5eba4
  3. Affected versionversion=8270d9c21041470f58348248b9d9dcf3bf79592e <1fab5ece76fb42a761178dcd0ebcbf578377b0dd
  4. Affected versionversion=8270d9c21041470f58348248b9d9dcf3bf79592e <6d5e4538364b9ceb1ac2941a4deb86650afb3538
  5. Affected versionversion=8270d9c21041470f58348248b9d9dcf3bf79592e <cadf3da46c15523fba90d80c9955f536ee3b4023
  6. Affected versionversion=8270d9c21041470f58348248b9d9dcf3bf79592e <f00fc26c8a06442b225a350fe000c0a11483e6a3
  7. Affected versionversion=8270d9c21041470f58348248b9d9dcf3bf79592e <fd7579f0a2c84ba8a7d4f206201b50dc8ddf90c2
  8. Affected versionversion=ebfee3e153f67c8b38eb94a7062ee94aa6f92708

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.18; version=8270d9c21041470f58348248b9d9dcf3bf79592e <1e4f873879e075bbd4eb1c644d6933303ac5eba4; version=8270d9c21041470f58348248b9d9dcf3bf79592e <1fab5ece76fb42a761178dcd0ebcbf578377b0dd; version=8270d9c21041470f58348248b9d9dcf3bf79592e <6d5e4538364b9ceb1ac2941a4deb86650afb3538; version=8270d9c21041470f58348248b9d9dcf3bf79592e <cadf3da46c15523fba90d80c9955f536ee3b4023; version=8270d9c21041470f58348248b9d9dcf3bf79592e <f00fc26c8a06442b225a350fe000c0a11483e6a3; version=8270d9c21041470f58348248b9d9dcf3bf79592e <fd7579f0a2c84ba8a7d4f206201b50dc8ddf90c2; version=ebfee3e153f67c8b38eb94a7062ee94aa6f92708

Published CVSS scores

7.0Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
9.8Linux Kernel CNACVSS: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

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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 exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

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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