CVE-2026-43417

System stall via incomplete vfork CID fixup

Published May 8, 2026 · Updated May 8, 2026

A scheduler denial of service in Linux Kernel 6.19 through 6.19.8 allows local users to stall the machine via vfork or CLONE_VM. The mm_get_cid() recovery path double-counts processed tasks and can stop its task-list walk before fixing the vforked task's CID. A local low-privileged task must create the shared-memory condition; a later schedule-in then loops indefinitely and stalls the entire machine.

CVSS severity5.5
Medium
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A scheduler denial of service in Linux Kernel 6.19 through 6.19.8 allows local users to stall the machine via vfork or CLONE_VM. The mm_get_cid() recovery path double-counts processed tasks and can stop its task-list walk before fixing the vforked task's CID. A local low-privileged task must create the shared-memory condition; a later schedule-in then loops indefinitely and stalls the entire machine.

The record

CVE
CVE-2026-43417
Published
May 8, 2026
Updated
May 8, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 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=6.19
  2. Affected versionversion=fbd0e71dc370af73f6b316e4de9eed273dd90340 <28b5a1395036d6c7a6c8034d85ad3d7d365f192c
  3. Affected versionversion=fbd0e71dc370af73f6b316e4de9eed273dd90340 <e6761cdce78a8919a537989afb6aaf6881469f83

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.19; version=fbd0e71dc370af73f6b316e4de9eed273dd90340 <28b5a1395036d6c7a6c8034d85ad3d7d365f192c; version=fbd0e71dc370af73f6b316e4de9eed273dd90340 <e6761cdce78a8919a537989afb6aaf6881469f83

Published CVSS scores

5.5Amazon LinuxCVSS: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.

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

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

No sourced classifications are available.

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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