CVE-2026-55005: Microsoft Exchange Server Remote Code Execution Vulnerability

Overview

Severity
High (CVSS 8.8)
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Category
Remote Code Execution
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2026-Jul
Released
2026-07-14

Description

Heap-based buffer overflow in Microsoft Exchange Server allows an authorized attacker to execute code over a network.

Affected Products (4)

ESU

  • Microsoft Exchange Server 2016 Cumulative Update 23
  • Microsoft Exchange Server 2019 Cumulative Update 15
  • Microsoft Exchange Server 2019 Cumulative Update 14

Server Software

  • Microsoft Exchange Server Subscription Edition RTM

Security Updates (1)

Acknowledgments

kunlun Lab & GLM, kunlun Lab & GLM

Revision History

  • 2026-07-14: Information published.