Microsoft Security Response CenterCVE-2026-87696

Microsoft Exchange Server Elevation of Privilege Vulnerability

HighVendor CVSS 7.5 / 10 1 CVE Published Oct 13, 2026 at 7:00 AM UTC

Summary

Improper verification of cryptographic signature in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.

Install KB5128896. Install KB5128895. Install KB5128897. Install KB5128898.

Oct 13, 2026 at 7:00 AM UTC
Published by Microsoft Security Response Center
The publication date reported by the vendor.
Oct 13, 2026 at 10:55 PM UTC
Added to SecurityAlert
We collected the advisory from the official source.
Oct 21, 2026 at 1:15 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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