CVE-2023-53496

Local denial of service via incomplete socket tables

Published Oct 1, 2025 · Updated May 11, 2026

Denial of service in Linux kernel 6.5 through 6.5.4 allows local users to trigger a kernel oops through incomplete SGI UV socket-to-node tables. The build_socket_tables() routine skips nodes or sockets when nr_cpus disables present CPUs, leaving -1 entries that later lookup code consumes. Reachability requires an x86 SGI UV system configured with nr_cpus below the installed CPU count, and the resulting oops interrupts the host.

CVSS severity5.5
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Linux kernel 6.5 through 6.5.4 allows local users to trigger a kernel oops through incomplete SGI UV socket-to-node tables. The build_socket_tables() routine skips nodes or sockets when nr_cpus disables present CPUs, leaving -1 entries that later lookup code consumes. Reachability requires an x86 SGI UV system configured with nr_cpus below the installed CPU count, and the resulting oops interrupts the host.

The record

CVE
CVE-2023-53496
Published
Oct 1, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 1, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=6.5
  2. Affected versionversion=8a50c58519271dd24ba760bb282875f6ad66ee71 <0d01a0c3046d1545391ef7bb1f114743d00e3793
  3. Affected versionversion=8a50c58519271dd24ba760bb282875f6ad66ee71 <5290e88ba2c742ca77c5f5b690e5af549cfd8591

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.5; version=8a50c58519271dd24ba760bb282875f6ad66ee71 <0d01a0c3046d1545391ef7bb1f114743d00e3793; version=8a50c58519271dd24ba760bb282875f6ad66ee71 <5290e88ba2c742ca77c5f5b690e5af549cfd8591

Published CVSS scores

5.5CanonicalCVSS:3.1/AV:L/AC:L/PR:L/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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