CVE-2026-69382: Microsoft Exchange Server Information Disclosure Vulnerability

Overview

Severity
Medium (CVSS 5.9)
CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
Category
Information Disclosure
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2026-Sep
Released
2026-09-08

Description

Use of a broken or risky cryptographic algorithm in Microsoft Exchange Server allows an unauthorized attacker to disclose information over a network.

FAQ

What type of information could be disclosed by this vulnerability? Exploiting this vulnerability could allow the disclosure of credentials. According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability? Successful exploitation requires an attacker to first obtain a valid encrypted authentication cookie through a separate compromise and then make repeated requests to infer the protected credentials. These additional prerequisites make exploitation difficult and time-consuming.

Affected Products (4)

ESU

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

Server Software

  • Microsoft Exchange Server Subscription Edition RTM

Security Updates (1)

Acknowledgments

Michael Maturi with <a href="https://google.com/">Google/Mandiant</a>

Revision History

  • 2026-09-08: Information published.