CVE-2023-53439

Local kernel crash via reserved transport offset

Published Sep 18, 2025 · Updated Sep 18, 2025

An input-validation flaw in affected Linux kernel releases allows local users to crash the kernel through a crafted packet checksum. The skb_partial_csum_set function accepts a calculated checksum start of 0xFFFF and stores that reserved unset sentinel in skb->transport_header. Triggering the warning path requires local low-privilege packet transmission with fuzzer-like checksum offsets; published metrics report availability loss without data disclosure or modification.

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

An input-validation flaw in affected Linux kernel releases allows local users to crash the kernel through a crafted packet checksum. The skb_partial_csum_set function accepts a calculated checksum start of 0xFFFF and stores that reserved unset sentinel in skb->transport_header. Triggering the warning path requires local low-privilege packet transmission with fuzzer-like checksum offsets; published metrics report availability loss without data disclosure or modification.

The record

CVE
CVE-2023-53439
Published
Sep 18, 2025
Updated
Sep 18, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-401, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 18, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 2025Record 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=5.19
  2. Affected versionversion=66e4c8d950083df8e12981babca788e1635c92b6 <3e785c8deb046305c61b9fa02265d0cb900c4a45
  3. Affected versionversion=66e4c8d950083df8e12981babca788e1635c92b6 <424f8416bb39936df6365442d651ee729b283460
  4. Affected versionversion=66e4c8d950083df8e12981babca788e1635c92b6 <70a76d6816148819d0464f71aafa126c84826628

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.19; version=66e4c8d950083df8e12981babca788e1635c92b6 <3e785c8deb046305c61b9fa02265d0cb900c4a45; version=66e4c8d950083df8e12981babca788e1635c92b6 <424f8416bb39936df6365442d651ee729b283460; version=66e4c8d950083df8e12981babca788e1635c92b6 <70a76d6816148819d0464f71aafa126c84826628

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5CISA ADP VulnrichmentCVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

CWE-401Missing Release of Memory after Effective Lifetime
T1499Endpoint Denial of Service

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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