High · 7.5 CVE-2026-69378 EUVD-2026-73128GHSA-hp6f-8h4f-5pjq

Microsoft Exchange Server Denial of Service Vulnerability

Published Sep 8, 2026 · Updated Nov 10, 2026 · Assigned by microsoft

Vendor: Microsoft Product: Microsoft Exchange Server 2016 Cumulative Update 23 Product: Microsoft Exchange Server 2019 Cumulative Update 14 Product: Microsoft Exchange Server 2019 Cumulative Update 15 Product: Microsoft Exchange Server Subscription Edition RTM

Description

Uncontrolled recursion in Microsoft Exchange Server allows an unauthorized attacker to deny service over a network.

Affected products

Vendor	Product	Affected	Fixed
Microsoft	Microsoft Exchange Server 2016 Cumulative Update 23	15.01.0.0 – < 15.01.2507.073	15.01.2507.073
Microsoft	Microsoft Exchange Server 2019 Cumulative Update 14	15.02.0.0 – < 15.02.1544.046	15.02.1544.046
Microsoft	Microsoft Exchange Server 2019 Cumulative Update 15	15.02.0.0 – < 15.02.1748.051	15.02.1748.051
Microsoft	Microsoft Exchange Server Subscription Edition RTM	15.02.0.0 – < 15.02.2562.049	15.02.2562.049

Advisories 4

WID-SEC-2026-3243 Microsoft Windows: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 4, 2026
WID-SEC-2026-3268 Microsoft Exchange Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Sep 8, 2026
NCSC-2026-0349 Kwetsbaarheden verholpen in Microsoft Exchange server NCSC-NL (Netherlands) · Sep 8, 2026
MSRC-CVE-2026-69378 Microsoft Exchange Server Denial of Service Vulnerability Microsoft Security Response Center · Sep 8, 2026

References

Microsoft Exchange Server Denial of Service Vulnerability vendor-advisory patch