CVE-2023-53669

System crash via undersized skb payload allocation

Published Oct 7, 2025 · Updated Oct 7, 2025

Denial of service in Linux kernel 5.19 before 6.4 allows local users to crash the system through oversized zero-copy TCP skbs. The skb_copy_ubufs() path assumes MAX_SKB_FRAGS order-0 pages can hold the entire payload, although BIG TCP permits an skb as large as 512 KB. The crash requires TCP transmit zerocopy with hugepages and an skb above roughly 68 KB; smaller configured GSO limits avoid the affected path.

CVSS severity5.5
Medium
EPSS probability0.15%
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 5.19 before 6.4 allows local users to crash the system through oversized zero-copy TCP skbs. The skb_copy_ubufs() path assumes MAX_SKB_FRAGS order-0 pages can hold the entire payload, although BIG TCP permits an skb as large as 512 KB. The crash requires TCP transmit zerocopy with hugepages and an skb above roughly 68 KB; smaller configured GSO limits avoid the affected path.

The record

CVE
CVE-2023-53669
Published
Oct 7, 2025
Updated
Oct 7, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-401, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 7, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 7, 2025Record 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=5.19
  2. Affected versionversion=7c4e983c4f3cf94fcd879730c6caa877e0768a4d <3c77a377877acbaf03cd7caa21d3644a5dd16301
  3. Affected versionversion=7c4e983c4f3cf94fcd879730c6caa877e0768a4d <7e692df3933628d974acb9f5b334d2b3e885e2a6
  4. Affected versionversion=7c4e983c4f3cf94fcd879730c6caa877e0768a4d <7fa93e39fbb0566019c388a8038a4d58552e0910
  5. Affected versionversion=7c4e983c4f3cf94fcd879730c6caa877e0768a4d <9cd62f0ba465cf647c7d8c2ca7b0d99ea0c1328f

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.19; version=7c4e983c4f3cf94fcd879730c6caa877e0768a4d <3c77a377877acbaf03cd7caa21d3644a5dd16301; version=7c4e983c4f3cf94fcd879730c6caa877e0768a4d <7e692df3933628d974acb9f5b334d2b3e885e2a6; version=7c4e983c4f3cf94fcd879730c6caa877e0768a4d <7fa93e39fbb0566019c388a8038a4d58552e0910; version=7c4e983c4f3cf94fcd879730c6caa877e0768a4d <9cd62f0ba465cf647c7d8c2ca7b0d99ea0c1328f

Published CVSS scores

5.5NVDCVSS: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

CWE-401Missing Release of Memory after Effective Lifetime
T1499.004Application or System Exploitation

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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