CVE-2026-64523Network attack vector

Kernel compromise via socket-file lifetime race

Published Jul 25, 2026 · Updated Jul 25, 2026

Use-after-free in Linux Kernel branches starting at 6.4 allows remote attackers to compromise the kernel via a socket-file lifetime race. handshake_nl_accept_doit() retains req->hr_sk->sk_socket without a file reference, allowing sock_release() to free the socket before FD_PREPARE() and get_file() dereference it. Exploitation requires a network-facing NFS/RPC-over-TLS or TLS-enabled NVMe/TCP consumer and a disconnect or timeout while the trusted handshake daemon accepts the request.

CVSS severity9.8
Critical
EPSS probability0.36%
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 branches starting at 6.4 allows remote attackers to compromise the kernel via a socket-file lifetime race. handshake_nl_accept_doit() retains req->hr_sk->sk_socket without a file reference, allowing sock_release() to free the socket before FD_PREPARE() and get_file() dereference it. Exploitation requires a network-facing NFS/RPC-over-TLS or TLS-enabled NVMe/TCP consumer and a disconnect or timeout while the trusted handshake daemon accepts the request.

The record

CVE
CVE-2026-64523
Published
Jul 25, 2026
Updated
Jul 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-825, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 25, 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=0 <6.12.93
  2. Affected versionversion=0 <7.0.12
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <09dba37eee70d0596e26645015f1aa95a9848e9d
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <16eaba5aa89c04eea125905bb8f988c1897f4f29
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <685b10dd0e32c7782cead16c8cf055c609678583

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0 <6.12.93; version=0 <7.0.12; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <09dba37eee70d0596e26645015f1aa95a9848e9d; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <16eaba5aa89c04eea125905bb8f988c1897f4f29; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <685b10dd0e32c7782cead16c8cf055c609678583

Published CVSS scores

9.8Linux kernel CVE teamCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.0Red HatCVSS:3.1/AV:L/AC:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-825Expired Pointer Dereference
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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