CVE-2023-52996

Kernel-memory disclosure via speculative route-metric index

Published Mar 27, 2025 · Updated May 11, 2026

Information disclosure in affected Linux kernel versions allows local users to read kernel memory during IPv4 route-metric processing. In fib_metrics_match(), the kernel bounds-checks the metric type but uses type minus one as an array index without constraining speculative execution. Successful exploitation requires local low-privileged access and control of the metric type; the documented consequence is kernel-memory exposure.

CVSS severity5.5
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in affected Linux kernel versions allows local users to read kernel memory during IPv4 route-metric processing. In fib_metrics_match(), the kernel bounds-checks the metric type but uses type minus one as an array index without constraining speculative execution. Successful exploitation requires local low-privileged access and control of the metric type; the documented consequence is kernel-memory exposure.

The record

CVE
CVE-2023-52996
Published
Mar 27, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 27, 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

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=4.14
  2. Affected versionversion=5f9ae3d9e7e4ad6db0491abc7c4ae5452dbeadd8 <5e9398a26a92fc402d82ce1f97cc67d832527da0
  3. Affected versionversion=5f9ae3d9e7e4ad6db0491abc7c4ae5452dbeadd8 <7f9828fb1f688210e681268490576f0ca65c322a
  4. Affected versionversion=5f9ae3d9e7e4ad6db0491abc7c4ae5452dbeadd8 <8f0eb24f1a7a60ce635f0d757a46f1a37a4d467d
  5. Affected versionversion=5f9ae3d9e7e4ad6db0491abc7c4ae5452dbeadd8 <ca3cf947760de050d558293002ad3e7f4b8745d2
  6. Affected versionversion=5f9ae3d9e7e4ad6db0491abc7c4ae5452dbeadd8 <f9753ebd61be2d957b5504cbd3fd719674f05b7a

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.14; version=5f9ae3d9e7e4ad6db0491abc7c4ae5452dbeadd8 <5e9398a26a92fc402d82ce1f97cc67d832527da0; version=5f9ae3d9e7e4ad6db0491abc7c4ae5452dbeadd8 <7f9828fb1f688210e681268490576f0ca65c322a; version=5f9ae3d9e7e4ad6db0491abc7c4ae5452dbeadd8 <8f0eb24f1a7a60ce635f0d757a46f1a37a4d467d; version=5f9ae3d9e7e4ad6db0491abc7c4ae5452dbeadd8 <ca3cf947760de050d558293002ad3e7f4b8745d2; version=5f9ae3d9e7e4ad6db0491abc7c4ae5452dbeadd8 <f9753ebd61be2d957b5504cbd3fd719674f05b7a

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.9Amazon LinuxCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
5.5UbuntuCVSS: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

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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

T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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