CVE-2026-93220Hinoki check available

CPU hang via foreign-CPU kick_sync callback

Published Sep 24, 2026 · Updated Sep 24, 2026

Linux sched_ext 6.19 contains a deadlock that allows attackers to hang a CPU via synchronous cross-CPU scheduler kicks. The kick_sync_wait_bal_cb() callback can run on a foreign CPU and compare unrelated per-CPU snapshots while waiting with the runqueue lock dropped, deadlocking when that CPU is also a wait target. Exposure requires sched_ext support and a loaded BPF scheduler, plus timing that flushes a queued balance callback on a different CPU.

CVSS severityUnavailable
Unscored
EPSS probability0.15%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Linux sched_ext 6.19 contains a deadlock that allows attackers to hang a CPU via synchronous cross-CPU scheduler kicks. The kick_sync_wait_bal_cb() callback can run on a foreign CPU and compare unrelated per-CPU snapshots while waiting with the runqueue lock dropped, deadlocking when that CPU is also a wait target. Exposure requires sched_ext support and a loaded BPF scheduler, plus timing that flushes a queued balance callback on a different CPU.

The record

CVE
CVE-2026-93220
Published
Sep 24, 2026
Updated
Sep 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 24, 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=4c95380701f58b8112f0b891de8d160e4199e19d <c736ea0fe7b4df920da6bd43a81c5eeecadcc8be
  2. Affected versionversion=4c95380701f58b8112f0b891de8d160e4199e19d <e0253dd04beb03e79477c5ef4768b11135687206
  3. Affected versionversion=6.19

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=4c95380701f58b8112f0b891de8d160e4199e19d <c736ea0fe7b4df920da6bd43a81c5eeecadcc8be; version=4c95380701f58b8112f0b891de8d160e4199e19d <e0253dd04beb03e79477c5ef4768b11135687206; version=6.19

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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
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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