Insufficient Granularity of Access Control in Microsoft Exchange Server - CVE-2026-55006
Published: July 16, 2026
Vulnerability identifier: #VU137891
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-55006
CWE-ID: CWE-1220
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Microsoft
Affected software:
Microsoft Exchange Server
Microsoft Exchange Server
Detailed vulnerability description
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to insufficient granularity of access control in Microsoft Exchange Server, which leads to security restrictions bypass and privilege escalation.
How to mitigate CVE-2026-55006
Install updates from vendor's website.