CVE-2026-74662Network attack vector

Kernel memory corruption via fragment-queue timer race

Published Aug 22, 2026 · Updated Aug 27, 2026

Race condition in the Linux kernel's IP fragment reassembly code allows remote attackers to corrupt kernel memory via crafted fragments. inet_frag_create() arms a new fragment queue's timer before publishing the queue in the fqdir rhashtable, letting immediate expiry drop a planned hash reference and leave a stale node. When a network namespace's fragment timeout is zero or negative, later lookups can read or write freed memory, execute code in the kernel, or crash the host.

CVSS severity9.8
Critical
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in the Linux kernel's IP fragment reassembly code allows remote attackers to corrupt kernel memory via crafted fragments. inet_frag_create() arms a new fragment queue's timer before publishing the queue in the fqdir rhashtable, letting immediate expiry drop a planned hash reference and leave a stale node. When a network namespace's fragment timeout is zero or negative, later lookups can read or write freed memory, execute code in the kernel, or crash the host.

The record

CVE
CVE-2026-74662
Published
Aug 22, 2026
Updated
Aug 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-367, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 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=4.17
  2. Affected versionversion=4.4.174 <4.5
  3. Affected versionversion=493107105843f299662b3b664a83804645564f12
  4. Affected versionversion=648700f76b03b7e8149d13cc2bdb3355035258a9 <08a04d7bfb9c103432561aff8a62b6872e694a6a
  5. Affected versionversion=648700f76b03b7e8149d13cc2bdb3355035258a9 <39c6c4b267b65f00e0b0335a2ae00cbe9e3174f0
  6. Affected versionversion=648700f76b03b7e8149d13cc2bdb3355035258a9 <4ed0681dc2c1e0538b79d2fc56190ffcb369dacd
  7. Affected versionversion=648700f76b03b7e8149d13cc2bdb3355035258a9 <653d7ddf6cba867777a3d14c4f83ace008c5ad13
  8. Affected versionversion=648700f76b03b7e8149d13cc2bdb3355035258a9 <928128865e43b197e30688dc1bc991592c97edcf
  9. Affected versionversion=648700f76b03b7e8149d13cc2bdb3355035258a9 <9f904dd3e455750e5d4ec9b2f134835811b85a2f
  10. Affected versionversion=648700f76b03b7e8149d13cc2bdb3355035258a9 <d3ffb89b2944672cf7bdd8e9ee577d2043b4a956
  11. Affected versionversion=648700f76b03b7e8149d13cc2bdb3355035258a9 <f4e4dab62181b7fe7c011bed6fbef9fc3d48c769

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.17; version=4.4.174 <4.5; version=493107105843f299662b3b664a83804645564f12; version=648700f76b03b7e8149d13cc2bdb3355035258a9 <08a04d7bfb9c103432561aff8a62b6872e694a6a; version=648700f76b03b7e8149d13cc2bdb3355035258a9 <39c6c4b267b65f00e0b0335a2ae00cbe9e3174f0; version=648700f76b03b7e8149d13cc2bdb3355035258a9 <4ed0681dc2c1e0538b79d2fc56190ffcb369dacd; version=648700f76b03b7e8149d13cc2bdb3355035258a9 <653d7ddf6cba867777a3d14c4f83ace008c5ad13; version=648700f76b03b7e8149d13cc2bdb3355035258a9 <928128865e43b197e30688dc1bc991592c97edcf; version=648700f76b03b7e8149d13cc2bdb3355035258a9 <9f904dd3e455750e5d4ec9b2f134835811b85a2f; version=648700f76b03b7e8149d13cc2bdb3355035258a9 <d3ffb89b2944672cf7bdd8e9ee577d2043b4a956; version=648700f76b03b7e8149d13cc2bdb3355035258a9 <f4e4dab62181b7fe7c011bed6fbef9fc3d48c769

Published CVSS scores

9.8LinuxCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.0Red HatCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
T1190Exploit Public-Facing Application

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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