Main Vulnerability Database Vulnerabilities #VU155257

Deserialization of Untrusted Data in Microsoft Exchange Server and Microsoft Exchange Server Subscription Edition RTM - CVE-2026-87692

Published: October 14, 2026

Vulnerability identifier: #VU155257

CSH Severity: Low

CVSS v4: 8.5 [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]

CVE-ID: CVE-2026-87692

CWE-ID: CWE-502

Exploitation vector: Local access

Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to escalate privileges to SYSTEM.

The vulnerability exists due to deserialization of untrusted data in Microsoft Exchange Server when processing untrusted serialized data. A local user can exploit this deserialization flaw to escalate privileges to SYSTEM.

Affected software

Microsoft Exchange Server
Microsoft Exchange Server Subscription Edition RTM

How to mitigate CVE-2026-87692

Install security update from vendor's website.

Microsoft Exchange Server - addressed in versions 15.01.2507.077, 15.02.1544.050
Microsoft Exchange Server Subscription Edition RTM - update to 15.02.2562.056

External References

Related Security Bulletins