CVE-2026-99103

Unspecified impact via stale worker-pool lock access

Published Oct 28, 2026 · Updated Oct 28, 2026

Use-after-free in Linux workqueues allows attackers to cause unspecified impact via access to a freed unbound worker-pool lock. After cancellation leaves an empty pool-workqueue on pending_pwqs, pwq_release_workfn() drops the pool reference before unlinking it, allowing node_activate_pending_pwq() to access the freed lock. The trigger requires cancellation of the last inactive work and release of the last pool reference; attacker privileges and consequences beyond the reported invalid memory access are not documented.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Nov 1, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux workqueues allows attackers to cause unspecified impact via access to a freed unbound worker-pool lock. After cancellation leaves an empty pool-workqueue on pending_pwqs, pwq_release_workfn() drops the pool reference before unlinking it, allowing node_activate_pending_pwq() to access the freed lock. The trigger requires cancellation of the last inactive work and release of the last pool reference; attacker privileges and consequences beyond the reported invalid memory access are not documented.

The record

CVE
CVE-2026-99103
Published
Oct 28, 2026
Updated
Oct 28, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 28, 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=5797b1c18919cd9c289ded7954383e499f729ce0 <3d2ef2b9f4c084ab498494d26495a82f7e15407b
  2. Affected versionversion=5797b1c18919cd9c289ded7954383e499f729ce0 <cf9c8aaea0d47410df8708bec195889f3a85cd3c
  3. Affected versionversion=5797b1c18919cd9c289ded7954383e499f729ce0 <f320b85c90fe5fc9d4d06badd450518323a94a7f
  4. Affected versionversion=5a70baec2294e8a7d0fcc4558741c23e752dad5c <6741dd3fd38e47c08bc39d11ef5fa141fa6d0441
  5. Affected versionversion=6.6.23 <6.6.25
  6. Affected versionversion=6.7.11 <6.8
  7. Affected versionversion=6.8.2 <6.8.4
  8. Affected versionversion=6.9
  9. Affected versionversion=843288afd3cc6f3342659c6cf81fc47684d25563 <9f5d5aef3072a33c6f9bfb954bb0cba1c2541849
  10. Affected versionversion=fc67aebe34f22632ccb22faea48cc4d3134620a2

What conditions does exploitation require?

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

What is affected?

The Linux Kernel Organization · Linuxversion=5797b1c18919cd9c289ded7954383e499f729ce0 <3d2ef2b9f4c084ab498494d26495a82f7e15407b; version=5797b1c18919cd9c289ded7954383e499f729ce0 <cf9c8aaea0d47410df8708bec195889f3a85cd3c; version=5797b1c18919cd9c289ded7954383e499f729ce0 <f320b85c90fe5fc9d4d06badd450518323a94a7f; version=5a70baec2294e8a7d0fcc4558741c23e752dad5c <6741dd3fd38e47c08bc39d11ef5fa141fa6d0441; version=6.6.23 <6.6.25; version=6.7.11 <6.8; version=6.8.2 <6.8.4; version=6.9; version=843288afd3cc6f3342659c6cf81fc47684d25563 <9f5d5aef3072a33c6f9bfb954bb0cba1c2541849; version=fc67aebe34f22632ccb22faea48cc4d3134620a2

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)
VectorUnavailable
PrivilegesUnavailable
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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