CVE-2026-55009: Microsoft Exchange Server Elevation of Privilege Vulnerability
Overview
- Severity
- High (CVSS 7.8)
- CVSS Vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
- Category
- Elevation of Privilege
- Exploit Status
- Not Exploited
- Exploitation Likelihood
- Unlikely
- Patch Tuesday
- 2026-Jul
- Released
- 2026-07-14
Description
Deserialization of untrusted data in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.
Affected Products (4)
ESU
- Microsoft Exchange Server 2016 Cumulative Update 23
- Microsoft Exchange Server 2019 Cumulative Update 14
- Microsoft Exchange Server 2019 Cumulative Update 15
Server Software
- Microsoft Exchange Server Subscription Edition RTM
Security Updates (1)
Acknowledgments
Anonymous
Revision History
- 2026-07-14: Information published.