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MicrosoftCVE-2026-55006

Microsoft Exchange Server: improper access control

High7.8CVE-2026-55006 · Published Jul 14, 2026 · updated Jul 24, 2026

Insufficient granularity of access control in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.

Microsoft advisory

Affected versions

PackageAffectedFixed in
Microsoft Exchange Server 2016 Cumulative Update 23
Product
>= 15.01.0.0, < 15.01.2507.07115.01.2507.071
Microsoft Exchange Server 2019 Cumulative Update 14
Product
>= 15.02.0.0, < 15.02.1544.04315.02.1544.043
Microsoft Exchange Server 2019 Cumulative Update 15
Product
>= 15.02.0.0, < 15.02.1748.04815.02.1748.048
Microsoft Exchange Server Subscription Edition RTM
Product
>= 15.02.0.0, < 15.02.2562.04515.02.2562.045
Details and references
CVSS 3.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity from
the vendor (its own CVE record or advisory)
Weakness
CWE-1220

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