CVE-2025-68202

Kernel deadlock via non-IRQ-safe runqueue locking

Published Dec 16, 2025 · Updated Dec 16, 2025

Deadlock in sched_ext in Linux kernel 6.12 allows attackers to hang the system through a scheduler state dump on PREEMPT_RT builds. scx_dump_state acquires a runqueue lock without disabling interrupts, allowing an interrupt on the same CPU to reacquire that lock and deadlock. Reachability requires CONFIG_PREEMPT_RT=y and a sched_ext error or diagnostic dump; the documented consequence is a kernel scheduling hang.

CVSS severityUnavailable
Unscored
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deadlock in sched_ext in Linux kernel 6.12 allows attackers to hang the system through a scheduler state dump on PREEMPT_RT builds. scx_dump_state acquires a runqueue lock without disabling interrupts, allowing an interrupt on the same CPU to reacquire that lock and deadlock. Reachability requires CONFIG_PREEMPT_RT=y and a sched_ext error or diagnostic dump; the documented consequence is a kernel scheduling hang.

The record

CVE
CVE-2025-68202
Published
Dec 16, 2025
Updated
Dec 16, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Dec 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 16, 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=07814a9439a3b03d79a1001614b5bc1cab69bcec <13d1c96d3a9f208bc1aa8642f6362dca25a157d2
  2. Affected versionversion=07814a9439a3b03d79a1001614b5bc1cab69bcec <5f02151c411dda46efcc5dc57b0845efcdcfc26d
  3. Affected versionversion=07814a9439a3b03d79a1001614b5bc1cab69bcec <b6109750063d3b9aca1c57031213ac5485a06c54
  4. Affected versionversion=6.12

What conditions does exploitation require?

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

What is affected?

The Linux Kernel Organization · Linuxversion=07814a9439a3b03d79a1001614b5bc1cab69bcec <13d1c96d3a9f208bc1aa8642f6362dca25a157d2; version=07814a9439a3b03d79a1001614b5bc1cab69bcec <5f02151c411dda46efcc5dc57b0845efcdcfc26d; version=07814a9439a3b03d79a1001614b5bc1cab69bcec <b6109750063d3b9aca1c57031213ac5485a06c54; version=6.12

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)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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