CVE-2026-84520

Local kernel corruption via unchecked input size

Published Sep 14, 2026 · Updated Sep 14, 2026

A buffer overflow in AppleFDEKeyStore in Apple macOS before 27 allows local users to crash the system or corrupt kernel memory. AppleFDEKeyStore inadequately validates input size before processing it, allowing data to exceed its destination buffer. Exploitation requires local execution; Apple reports system termination or kernel-memory corruption, but not code execution or privilege gain.

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

A buffer overflow in AppleFDEKeyStore in Apple macOS before 27 allows local users to crash the system or corrupt kernel memory. AppleFDEKeyStore inadequately validates input size before processing it, allowing data to exceed its destination buffer. Exploitation requires local execution; Apple reports system termination or kernel-memory corruption, but not code execution or privilege gain.

The record

CVE
CVE-2026-84520
Published
Sep 14, 2026
Updated
Sep 14, 2026
Vendor
Apple
Product
macOS
Classifications
Unavailable
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.

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
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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Your stack

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