CVE-2026-74267Network attack vector

Kernel crash via premature parent queue deactivation

Published Aug 15, 2026 · Updated Aug 15, 2026

Memory corruption in Linux kernel sch_codel allows remote attackers to crash hosts by sending traffic through a configured QFQ parent. The peek path calls qdisc_tree_reduce_backlog before restoring qlen, so a false zero-length notification deactivates a parent class that still owns a packet. A QFQ or other qlen_notify parent with a CoDel child must already be configured; the published trace demonstrates a kernel crash.

CVSS severity9.8
Critical
EPSS probability0.71%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in Linux kernel sch_codel allows remote attackers to crash hosts by sending traffic through a configured QFQ parent. The peek path calls qdisc_tree_reduce_backlog before restoring qlen, so a false zero-length notification deactivates a parent class that still owns a packet. A QFQ or other qlen_notify parent with a CoDel child must already be configured; the published trace demonstrates a kernel crash.

The record

CVE
CVE-2026-74267
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-805, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 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=2f9761a94bae33d26e6a81b31b36e7d776d93dc1 <e8c6dbadf139cb14ea6ed14add6ed6e88504dedd
  2. Affected versionversion=342debc12183b51773b3345ba267e9263bdfaaef <52f1da34c9f4d5bdc1e8b44242da5c7ba8db85f3
  3. Affected versionversion=342debc12183b51773b3345ba267e9263bdfaaef <755108bb7a5083e911294c416cfea605dc75632f
  4. Affected versionversion=342debc12183b51773b3345ba267e9263bdfaaef <91e0a793a72374c20ab31a40ccec21373e82e973
  5. Affected versionversion=4d55144b12e742404bb3f8fee6038bafbf45619d <e4615aa6bb7802944ae790cb4b3ef8c1b7491af3
  6. Affected versionversion=5.10.241 <5.10.261
  7. Affected versionversion=5.15.190 <5.15.212
  8. Affected versionversion=5.4.297 <5.5
  9. Affected versionversion=6.1.135 <6.1.178
  10. Affected versionversion=6.12.24 <6.12.97
  11. Affected versionversion=6.13.12 <6.14
  12. Affected versionversion=6.14.3 <6.15
  13. Affected versionversion=6.15
  14. Affected versionversion=6.6.88 <6.6.145
  15. Affected versionversion=7a742a9506849d1c1aa71e36c89855ceddc7d58e
  16. Affected versionversion=829c49b6b2ff45b043739168fd1245e4e1a91a30 <eba49fd85995a3851c597fa2d214f8d21736e1d8
  17. Affected versionversion=a57fe60ef4cf96bfbb6b58397ec28bdb5a5c6b31
  18. Affected versionversion=cc71a757da78dd4aa1b4a9b19cb011833730ccf2 <bb9cfd874ee884117b33e92a002b9a45b48202f4
  19. Affected versionversion=e73c838c80dccb9e4f19becc11d9f3cb4a27d483
  20. Affected versionversion=eda741fe155ddf5ecd2dd3bfbd4fc3c0c7dbb450 <7a05af7f58566682b73578b72ca8e53a268c43bd

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2f9761a94bae33d26e6a81b31b36e7d776d93dc1 <e8c6dbadf139cb14ea6ed14add6ed6e88504dedd; version=342debc12183b51773b3345ba267e9263bdfaaef <52f1da34c9f4d5bdc1e8b44242da5c7ba8db85f3; version=342debc12183b51773b3345ba267e9263bdfaaef <755108bb7a5083e911294c416cfea605dc75632f; version=342debc12183b51773b3345ba267e9263bdfaaef <91e0a793a72374c20ab31a40ccec21373e82e973; version=4d55144b12e742404bb3f8fee6038bafbf45619d <e4615aa6bb7802944ae790cb4b3ef8c1b7491af3; version=5.10.241 <5.10.261; version=5.15.190 <5.15.212; version=5.4.297 <5.5; version=6.1.135 <6.1.178; version=6.12.24 <6.12.97; version=6.13.12 <6.14; version=6.14.3 <6.15; version=6.15; version=6.6.88 <6.6.145; version=7a742a9506849d1c1aa71e36c89855ceddc7d58e; version=829c49b6b2ff45b043739168fd1245e4e1a91a30 <eba49fd85995a3851c597fa2d214f8d21736e1d8; version=a57fe60ef4cf96bfbb6b58397ec28bdb5a5c6b31; version=cc71a757da78dd4aa1b4a9b19cb011833730ccf2 <bb9cfd874ee884117b33e92a002b9a45b48202f4; version=e73c838c80dccb9e4f19becc11d9f3cb4a27d483; version=eda741fe155ddf5ecd2dd3bfbd4fc3c0c7dbb450 <7a05af7f58566682b73578b72ca8e53a268c43bd

Published CVSS scores

5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
9.8Linux Kernel CNACVSS:3.1/AV:N/AC:L/PR:N/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.

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-805Buffer Access with Incorrect Length Value
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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