CVE-2026-80630

Kernel crash via premature parent-class deactivation

Published Aug 28, 2026 · Updated Aug 28, 2026

Wild memory access in Linux fq_codel allows local users to crash the kernel through a crafted traffic-control queue hierarchy. When fq_codel drops a packet during peek, it reduces the parent backlog before restoring qlen; a transient zero triggers qlen_notify and wrongly deactivates a class that still owns a packet. Reaching the fault requires administrative control of the affected qdisc hierarchy, and the demonstrated consequence is a general-protection fault rather than disclosed code execution.

CVSS severityUnavailable
Unscored
EPSS probability0.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Wild memory access in Linux fq_codel allows local users to crash the kernel through a crafted traffic-control queue hierarchy. When fq_codel drops a packet during peek, it reduces the parent backlog before restoring qlen; a transient zero triggers qlen_notify and wrongly deactivates a class that still owns a packet. Reaching the fault requires administrative control of the affected qdisc hierarchy, and the demonstrated consequence is a general-protection fault rather than disclosed code execution.

The record

CVE
CVE-2026-80630
Published
Aug 28, 2026
Updated
Aug 28, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Aug 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 28, 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=2f9761a94bae33d26e6a81b31b36e7d776d93dc1 <acc08a0c7f37ebb1901144e03a7cba7d4afd9203
  2. Affected versionversion=342debc12183b51773b3345ba267e9263bdfaaef <0500af8630c3253f0dde879bd3a73a06bb2f2b3f
  3. Affected versionversion=342debc12183b51773b3345ba267e9263bdfaaef <097f6fc7b1ae362dd7a9444b2572162fda73b284
  4. Affected versionversion=342debc12183b51773b3345ba267e9263bdfaaef <af54df2f44d9605614bc7ed96640302a240a9a62
  5. Affected versionversion=4d55144b12e742404bb3f8fee6038bafbf45619d <7c09843fd2b44d9bf0de798683861d1aecd62a08
  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 <94a5f1efdefb01f82cd228bf4e7ef1e8fc075c80
  17. Affected versionversion=a57fe60ef4cf96bfbb6b58397ec28bdb5a5c6b31
  18. Affected versionversion=cc71a757da78dd4aa1b4a9b19cb011833730ccf2 <3e515188393e62a718ccebee651ee74514104ff6
  19. Affected versionversion=e73c838c80dccb9e4f19becc11d9f3cb4a27d483
  20. Affected versionversion=eda741fe155ddf5ecd2dd3bfbd4fc3c0c7dbb450 <20dd591d8f951e1e6aca5052be8785e6181055e2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=2f9761a94bae33d26e6a81b31b36e7d776d93dc1 <acc08a0c7f37ebb1901144e03a7cba7d4afd9203; version=342debc12183b51773b3345ba267e9263bdfaaef <0500af8630c3253f0dde879bd3a73a06bb2f2b3f; version=342debc12183b51773b3345ba267e9263bdfaaef <097f6fc7b1ae362dd7a9444b2572162fda73b284; version=342debc12183b51773b3345ba267e9263bdfaaef <af54df2f44d9605614bc7ed96640302a240a9a62; version=4d55144b12e742404bb3f8fee6038bafbf45619d <7c09843fd2b44d9bf0de798683861d1aecd62a08; 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 <94a5f1efdefb01f82cd228bf4e7ef1e8fc075c80; version=a57fe60ef4cf96bfbb6b58397ec28bdb5a5c6b31; version=cc71a757da78dd4aa1b4a9b19cb011833730ccf2 <3e515188393e62a718ccebee651ee74514104ff6; version=e73c838c80dccb9e4f19becc11d9f3cb4a27d483; version=eda741fe155ddf5ecd2dd3bfbd4fc3c0c7dbb450 <20dd591d8f951e1e6aca5052be8785e6181055e2

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

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)
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.

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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