Microsoft Security Response CenterCVE-2026-55009

Microsoft Exchange Server Elevation of Privilege Vulnerability

HighVendor CVSS 7.8 / 10 1 CVE Published Jul 14, 2026 at 7:00 AM UTC

Summary

Deserialization of untrusted data in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.

Install KB5103215. Install KB5103214. Install KB5103212. Install KB5103213.

Jul 14, 2026 at 7:00 AM UTC
Published by Microsoft Security Response Center
The publication date reported by the vendor.
Sep 28, 2026 at 11:20 AM UTC
Added to SecurityAlert
We collected the advisory from the official source.
Nov 11, 2026 at 2:20 AM UTC
Confirmed at the source
Our collector saw this advisory during a later source check.

Details collected from Microsoft Security Response Center.

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