CVE-2026-28976

Local root escalation via undisclosed information leakage

Published May 11, 2026 · Updated May 11, 2026

Information leakage in UserAccountUpdater in Apple macOS before 26.5 allows local users to gain root privileges through an app. Apple identifies additional validation in UserAccountUpdater but has not disclosed what information leaks or which untrusted value is accepted. Exploitation requires code execution as a local app; successful use elevates that app to root, while no remote path or additional impact has been reported.

CVSS severity7.5
High
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information leakage in UserAccountUpdater in Apple macOS before 26.5 allows local users to gain root privileges through an app. Apple identifies additional validation in UserAccountUpdater but has not disclosed what information leaks or which untrusted value is accepted. Exploitation requires code execution as a local app; successful use elevates that app to root, while no remote path or additional impact has been reported.

The record

CVE
CVE-2026-28976
Published
May 11, 2026
Updated
May 11, 2026
Vendor
Apple
Product
macOS
Classifications
CWE-269, CWE-200, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 11, 2026CVE publishedPublication date reported by the CVE source.
  2. May 11, 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 <26.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Apple · macOSversion=0 <26.5

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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

CWE-269Improper Privilege Management
CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1068Exploitation for Privilege Escalation

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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