CVE-2026-64541Network attack vector

Kernel memory corruption via unpinned SMC-R socket

Published Jul 27, 2026 · Updated Jul 27, 2026

Use-after-free in the Linux Kernel SMC-R receive path allows remote attackers to corrupt kernel memory via crafted CDC messages. The smc_cdc_rx_handler function releases conns_lock before pinning the selected smc_sock, so concurrent teardown frees it before sock_hold dereferences it. Exposure requires SMC-R over RDMA, and successful exploitation yields kernel-memory disclosure, overwrite, or a host crash.

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-R receive path allows remote attackers to corrupt kernel memory via crafted CDC messages. The smc_cdc_rx_handler function releases conns_lock before pinning the selected smc_sock, so concurrent teardown frees it before sock_hold dereferences it. Exposure requires SMC-R over RDMA, and successful exploitation yields kernel-memory disclosure, overwrite, or a host crash.

The record

CVE
CVE-2026-64541
Published
Jul 27, 2026
Updated
Jul 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 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=4.18
  2. Affected versionversion=d7b0e37c1ac152905b18a5b9506179091a35b0b6 <1951bffbc6493ec34cff3956b29d4bc6606904a6
  3. Affected versionversion=d7b0e37c1ac152905b18a5b9506179091a35b0b6 <3bfb96d9bc6a7ed0b99c7db329cc2e22a28d84bb
  4. Affected versionversion=d7b0e37c1ac152905b18a5b9506179091a35b0b6 <472e9d7c0d5b03be3ff91ff941f57da822b031bc
  5. Affected versionversion=d7b0e37c1ac152905b18a5b9506179091a35b0b6 <647b19e5cc145a2f1f685ae8ff3805a17356888c
  6. Affected versionversion=d7b0e37c1ac152905b18a5b9506179091a35b0b6 <8145b432136285e01091815b48ceb2dae261f262
  7. Affected versionversion=d7b0e37c1ac152905b18a5b9506179091a35b0b6 <8de4f665d0febfb92803dece377791a563fc7041
  8. Affected versionversion=d7b0e37c1ac152905b18a5b9506179091a35b0b6 <9d160b35cc34a2ba8229d07651468a7848325135
  9. Affected versionversion=d7b0e37c1ac152905b18a5b9506179091a35b0b6 <ce5aa8084329351086894aa34d77e40301d5bd3d

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.18; version=d7b0e37c1ac152905b18a5b9506179091a35b0b6 <1951bffbc6493ec34cff3956b29d4bc6606904a6; version=d7b0e37c1ac152905b18a5b9506179091a35b0b6 <3bfb96d9bc6a7ed0b99c7db329cc2e22a28d84bb; version=d7b0e37c1ac152905b18a5b9506179091a35b0b6 <472e9d7c0d5b03be3ff91ff941f57da822b031bc; version=d7b0e37c1ac152905b18a5b9506179091a35b0b6 <647b19e5cc145a2f1f685ae8ff3805a17356888c; version=d7b0e37c1ac152905b18a5b9506179091a35b0b6 <8145b432136285e01091815b48ceb2dae261f262; version=d7b0e37c1ac152905b18a5b9506179091a35b0b6 <8de4f665d0febfb92803dece377791a563fc7041; version=d7b0e37c1ac152905b18a5b9506179091a35b0b6 <9d160b35cc34a2ba8229d07651468a7848325135; version=d7b0e37c1ac152905b18a5b9506179091a35b0b6 <ce5aa8084329351086894aa34d77e40301d5bd3d

Published CVSS scores

9.8Linux kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
6.3Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/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

T1210Exploitation of Remote Services

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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