MSRC-CVE-2026-69375 — Microsoft Exchange Server Tampering Vulnerability

Summary

Impact: Tampering. Microsoft rating: Important. Not known to be exploited — Exploitation Less Likely. Customer action: Required.

Details

According to the CVSS metrics, successful exploitation of this vulnerability could lead to major loss of integrity (I:H). What does that mean for this vulnerability?
An authenticated attacker could replace valid file content with specially crafted file content.

According to the CVSS metric, privileges required is low (PR:L). What does that mean for this vulnerability?
Any authenticated attacker could trigger this vulnerability. It does not require admin or other elevated privileges.

Security updates
15.02.2562.049 — https://support.microsoft.com/help/5121608
15.02.1748.051 — https://support.microsoft.com/help/5121609
15.01.2507.073 — https://support.microsoft.com/help/5121611
15.02.1544.046 — https://support.microsoft.com/help/5121610

Vulnerabilities 1

Medium 6.5

CVE-2026-69375

Microsoft Exchange Server Tampering Vulnerability

Authorization bypass through user-controlled key in Microsoft Exchange Server allows an authorized attacker to perform tampering over a network.

Microsoft Microsoft Exchange Server 2016 Cumulative Update 23 Microsoft Exchange Server Subscription Edition RTM Microsoft Exchange Server 2019 Cumulative Update 14

Sep 8, 2026

Revision history

2026-09-08 #1
Information published.

References

CVE-2026-69375 Microsoft Exchange Server Tampering Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69375
Microsoft Exploitability Index
https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1
Microsoft Support Lifecycle
https://support.microsoft.com/lifecycle
Common Vulnerability Scoring System
https://www.first.org/cvss