CVE-2026-69378

Microsoft Exchange Server Denial of Service Vulnerability

State: Published
Severity: 7.5 High
Published: Sep 8, 2026
Updated: Oct 31, 2026
Reserved: Aug 3, 2026

Description

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

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C	microsoft

Weaknesses

CWE-674 Uncontrolled Recursion

Affected Products

Product	Versions
Microsoft Exchange Server 2016 Cumulative Update 23Microsoft	15.01.0.0 to before 15.01.2507.073Affected
Microsoft Exchange Server 2019 Cumulative Update 14Microsoft	15.02.0.0 to before 15.02.1544.046Affected
Microsoft Exchange Server 2019 Cumulative Update 15Microsoft	15.02.0.0 to before 15.02.1748.051Affected
Microsoft Exchange Server Subscription Edition RTMMicrosoft	15.02.0.0 to before 15.02.2562.049Affected

References

Microsoft Exchange Server Denial of Service Vulnerabilityvendor-advisorypatch

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