Authorization bypass through user-controlled key in Microsoft Exchange Server - CVE-2026-69375
Published: September 8, 2026
Vulnerability identifier: #VU147639
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-69375
CWE-ID: CWE-639
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to tamper with file content.
The vulnerability exists due to authorization bypass through a user-controlled key in Microsoft Exchange Server when handling network requests. A remote user can replace valid file content with specially crafted file content to tamper with file content.
Affected software
Microsoft Exchange Server
How to mitigate CVE-2026-69375
Install security update from vendor's website.
Microsoft Exchange Server - addressed in versions SE RTM Sep26SU 15.02.2562.049, 2016 CU23 Sep26SU 15.01.2507.073, 2019 CU14 Sep26SU 15.02.1544.046, 2019 CU15 Sep26SU 15.02.1748.051