CVE-2026-84558

System termination via kernel double free

Published Sep 14, 2026 · Updated Sep 14, 2026

Double free in the macOS kernel before 27 allows local users to cause unexpected system termination through an application. The kernel frees the same allocation twice, but Apple has not disclosed the affected function, object lifetime, or controllable input. Exploitation requires an application to execute locally; the documented consequence is system termination, with no reported code execution or data access.

CVSS severityUnavailable
Unscored
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Double free in the macOS kernel before 27 allows local users to cause unexpected system termination through an application. The kernel frees the same allocation twice, but Apple has not disclosed the affected function, object lifetime, or controllable input. Exploitation requires an application to execute locally; the documented consequence is system termination, with no reported code execution or data access.

The record

CVE
CVE-2026-84558
Published
Sep 14, 2026
Updated
Sep 14, 2026
Vendor
Apple
Product
macOS
Classifications
T1499.004
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 14, 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=0 <27

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Apple · macOSversion=0 <27

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)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application 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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