CVE-2026-80793Hinoki check available

Service hang via zero-length IPv4 fragments

Published Sep 4, 2026 · Updated Sep 4, 2026

Denial of service in affected Linux kernel branches allows local users to trigger a soft lockup through an undersized IPv4 MTU. ip_do_fragment() subtracts the IPv4 header length without rejecting an MTU below hlen plus eight, causing ip_frag_next() to round the payload length to zero while fragmentation state remains unchanged. Exploitation requires administrative control of a route or device MTU and interrupts service as the kernel repeatedly allocates and transmits header-only fragments.

CVSS severityUnavailable
Unscored
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Denial of service in affected Linux kernel branches allows local users to trigger a soft lockup through an undersized IPv4 MTU. ip_do_fragment() subtracts the IPv4 header length without rejecting an MTU below hlen plus eight, causing ip_frag_next() to round the payload length to zero while fragmentation state remains unchanged. Exploitation requires administrative control of a route or device MTU and interrupts service as the kernel repeatedly allocates and transmits header-only fragments.

The record

CVE
CVE-2026-80793
Published
Sep 4, 2026
Updated
Sep 4, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 4, 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?

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  1. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3556beb8ca86677af2aca5bfbed6f8e790fccc83
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <36e0741833bd823866f8cb9f112f37cea1a70b60
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <515b6816ba0c12d8415c88e5f41e6ec029e35cfa
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <74ce7389f8f562d39015f59a00ef7ad6acd37803
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a716a64a4ba68cd46f2745fba2b1099fe8e0aa59
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b0ea911453ce7210e8200a07a94d2458bd1e6430
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c0726f0caf8c6b3208552949e17d23634a2f3129
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c8a74adccaf028223054633b532593101dfcc581
  9. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d9d1a676b033acabf8e5645f730486d1f8204a3f
  10. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3556beb8ca86677af2aca5bfbed6f8e790fccc83; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <36e0741833bd823866f8cb9f112f37cea1a70b60; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <515b6816ba0c12d8415c88e5f41e6ec029e35cfa; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <74ce7389f8f562d39015f59a00ef7ad6acd37803; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a716a64a4ba68cd46f2745fba2b1099fe8e0aa59; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b0ea911453ce7210e8200a07a94d2458bd1e6430; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c0726f0caf8c6b3208552949e17d23634a2f3129; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c8a74adccaf028223054633b532593101dfcc581; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d9d1a676b033acabf8e5645f730486d1f8204a3f; version=2.6.12

Published CVSS scores

No CVSS assessment is available in this record.

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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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