CVE-2026-80866

Soft lockup via TIPC cleanup busy-wait

Published Sep 4, 2026 · Updated Sep 4, 2026

Denial of service in Linux kernel TIPC allows attackers to cause soft lockups during network-namespace exit with pending UDP cleanup. The tipc_exit_net() path busy-waits on wq_count with cond_resched(), which can become a no-op instead of yielding until cleanup finishes. The failure condition requires pending UDP bearer work and typically a high-priority exit task or CONFIG_PREEMPT_NONE; the bounded impact is prolonged CPU consumption and a soft lockup.

CVSS severityUnavailable
Unscored
EPSS probability0.14%
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 TIPC allows attackers to cause soft lockups during network-namespace exit with pending UDP cleanup. The tipc_exit_net() path busy-waits on wq_count with cond_resched(), which can become a no-op instead of yielding until cleanup finishes. The failure condition requires pending UDP bearer work and typically a high-priority exit task or CONFIG_PREEMPT_NONE; the bounded impact is prolonged CPU consumption and a soft lockup.

The record

CVE
CVE-2026-80866
Published
Sep 4, 2026
Updated
Sep 4, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
Unavailable
Privileges
Unavailable

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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=04c26faa51d1e2fe71cf13c45791f5174c37f986 <522d1d950b9e3b68190a6de7534827c8dccedb73
  2. Affected versionversion=04c26faa51d1e2fe71cf13c45791f5174c37f986 <c1481c94e74c955e0448ddf46b8615a44d840c1e
  3. Affected versionversion=5.10.42 <5.11
  4. Affected versionversion=5.12.9 <5.13
  5. Affected versionversion=5.13
  6. Affected versionversion=5195ec5e365a2a9331bfeb585b613a6e94f98dba
  7. Affected versionversion=5.4.124 <5.5
  8. Affected versionversion=b9f5b7ad4ac3af006443f535b1ce7bff1d130d7d
  9. Affected versionversion=d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=04c26faa51d1e2fe71cf13c45791f5174c37f986 <522d1d950b9e3b68190a6de7534827c8dccedb73; version=04c26faa51d1e2fe71cf13c45791f5174c37f986 <c1481c94e74c955e0448ddf46b8615a44d840c1e; version=5.10.42 <5.11; version=5.12.9 <5.13; version=5.13; version=5195ec5e365a2a9331bfeb585b613a6e94f98dba; version=5.4.124 <5.5; version=b9f5b7ad4ac3af006443f535b1ce7bff1d130d7d; version=d1f76dfadaf8f47ed1753f97dbcbd41c16215ffa

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)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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