CVE-2026-31733

Service interruption via stale direct dispatch state

Published May 1, 2026 · Updated May 1, 2026

Improper state cleanup in Linux Kernel allows local users to interrupt service by exercising sched_ext direct dispatch paths. The scheduler clears ddsp_dsq_id only in dispatch_enqueue(), leaving stale state when other paths consume, ignore, or cancel a direct-dispatch verdict. A later scx_bpf_dsq_insert() triggers WARN_ON_ONCE; a kernel panic requires panic_on_warn, while default configurations emit the warning once.

CVSS severity5.5
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper state cleanup in Linux Kernel allows local users to interrupt service by exercising sched_ext direct dispatch paths. The scheduler clears ddsp_dsq_id only in dispatch_enqueue(), leaving stale state when other paths consume, ignore, or cancel a direct-dispatch verdict. A later scx_bpf_dsq_insert() triggers WARN_ON_ONCE; a kernel panic requires panic_on_warn, while default configurations emit the warning once.

The record

CVE
CVE-2026-31733
Published
May 1, 2026
Updated
May 1, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 1, 2026CVE publishedPublication date reported by the CVE source.
  2. May 1, 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=5b26f7b920f76b2b9cc398c252a9e35e44bf5bb9 <5e7b2cc8fae9ec2a5bc53311191d2faaff75a4b5
  2. Affected versionversion=5b26f7b920f76b2b9cc398c252a9e35e44bf5bb9 <7e0ffb72de8aa3b25989c2d980e81b829c577010
  3. Affected versionversion=5b26f7b920f76b2b9cc398c252a9e35e44bf5bb9 <7ea601daa0153e19cd1c6e6b300348c70c05fe77
  4. Affected versionversion=5b26f7b920f76b2b9cc398c252a9e35e44bf5bb9 <ca685511f7afd42cdcbb0feea42e5d332d384251
  5. Affected versionversion=6.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5b26f7b920f76b2b9cc398c252a9e35e44bf5bb9 <5e7b2cc8fae9ec2a5bc53311191d2faaff75a4b5; version=5b26f7b920f76b2b9cc398c252a9e35e44bf5bb9 <7e0ffb72de8aa3b25989c2d980e81b829c577010; version=5b26f7b920f76b2b9cc398c252a9e35e44bf5bb9 <7ea601daa0153e19cd1c6e6b300348c70c05fe77; version=5b26f7b920f76b2b9cc398c252a9e35e44bf5bb9 <ca685511f7afd42cdcbb0feea42e5d332d384251; version=6.12

Published CVSS scores

5.5NIST NVDCVSS: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
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.

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Technologies

Your stack

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Your stack

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