CVE-2025-68333

System hang via deferred IRQ lock re-entry

Published Dec 22, 2025 · Updated Dec 22, 2025

Improper locking in Linux kernel sched_ext before 6.12.68, 6.13 through 6.17.11, and 6.18-rc1 through 6.18-rc6 allows local users to hang the system. The deferred_irq_workfn() can run in an irq_work task on PREEMPT_RT kernels and reacquire the current CPU runqueue __lock after an interrupt takes the same lock. Local low-privileged access and PREEMPT_RT with sched_ext activity are required; the recursive lock acquisition can deadlock the affected CPU and interrupt service.

CVSS severity5.5
Medium
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper locking in Linux kernel sched_ext before 6.12.68, 6.13 through 6.17.11, and 6.18-rc1 through 6.18-rc6 allows local users to hang the system. The deferred_irq_workfn() can run in an irq_work task on PREEMPT_RT kernels and reacquire the current CPU runqueue __lock after an interrupt takes the same lock. Local low-privileged access and PREEMPT_RT with sched_ext activity are required; the recursive lock acquisition can deadlock the affected CPU and interrupt service.

The record

CVE
CVE-2025-68333
Published
Dec 22, 2025
Updated
Dec 22, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-667, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 22, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 22, 2025Record 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <600b4379b9a7ba41340d652211fb29699da4c629
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a257e974210320ede524f340ffe16bf4bf0dda1e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <600b4379b9a7ba41340d652211fb29699da4c629; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a257e974210320ede524f340ffe16bf4bf0dda1e

Published CVSS scores

4.7SUSECVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
5.7SUSECVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-667Improper Locking
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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