CVE-2026-98220

Kernel crash via NULL scheduler error reporting

Published Oct 6, 2026 · Updated Oct 6, 2026

A NULL pointer dereference in Linux sched_ext 7.1 allows local users to crash the kernel through a BPF scheduler compatibility function. When a root scheduler has a sub-scheduler, scx_bpf_select_cpu_and() or scx_bpf_dsq_insert_vtime() passes a task's NULL scheduler to scx_error(), which reaches a dereference in scx_vexit(). Triggering the demonstrated path requires local BPF program execution and an exited-but-not-reaped task while a sub-scheduler is attached.

CVSS severityUnavailable
Unscored
EPSS probability0.20%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A NULL pointer dereference in Linux sched_ext 7.1 allows local users to crash the kernel through a BPF scheduler compatibility function. When a root scheduler has a sub-scheduler, scx_bpf_select_cpu_and() or scx_bpf_dsq_insert_vtime() passes a task's NULL scheduler to scx_error(), which reaches a dereference in scx_vexit(). Triggering the demonstrated path requires local BPF program execution and an exited-but-not-reaped task while a sub-scheduler is attached.

The record

CVE
CVE-2026-98220
Published
Oct 6, 2026
Updated
Oct 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 6, 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=7.1
  2. Affected versionversion=a5fa0708cbfda4d3c2c6a447de7c4b0b23595527 <0a85182723b65ad8bee8131bc38fcf0347d6679b
  3. Affected versionversion=a5fa0708cbfda4d3c2c6a447de7c4b0b23595527 <589f0945bf3ebf0790fd51e28c7f0d04ed3d8b78

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=7.1; version=a5fa0708cbfda4d3c2c6a447de7c4b0b23595527 <0a85182723b65ad8bee8131bc38fcf0347d6679b; version=a5fa0708cbfda4d3c2c6a447de7c4b0b23595527 <589f0945bf3ebf0790fd51e28c7f0d04ed3d8b78

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

T1499.004Endpoint Denial of Service: Application 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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