CVE-2026-69641: CWE-862: Missing Authorization in Microsoft Microsoft Exchange Server 2016 Cumulative Update 23
Description
CVE-2026-69641 is a critical vulnerability in Microsoft Exchange Server 2016 Cumulative Update 23 involving missing authorization. This flaw allows an authorized attacker to elevate privileges over a network, potentially leading to full compromise of confidentiality, integrity, and availability. The vulnerability affects multiple version ranges of Exchange Server 2016. An official fix is available from Microsoft.
CVSS v3.1
Score 9.1critical
Affected software
Microsoft
Microsoft Exchange Server 2016 Cumulative Update 23
Microsoft
Microsoft Exchange Server 2019 Cumulative Update 14
Microsoft
Microsoft Exchange Server 2019 Cumulative Update 15
Microsoft
Microsoft Exchange Server Subscription Edition RTM
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CWE-862) in Microsoft Exchange Server 2016 Cumulative Update 23 is due to missing authorization checks. An attacker with some level of authorization can exploit this flaw remotely to escalate privileges, resulting in complete compromise of the system's confidentiality, integrity, and availability. The CVSS 3.1 base score is 9.1, indicating critical severity. The affected versions include multiple builds prior to specific update versions within the 15.01.x and 15.02.x branches. Microsoft has published an official fix for this vulnerability.
Potential Impact
Exploitation of this vulnerability allows an authorized attacker to elevate their privileges over the network, potentially gaining full control over the affected Exchange Server. This can lead to complete compromise of data confidentiality, integrity, and availability on the server.
Mitigation Recommendations
An official fix is available from Microsoft. Administrators should apply the security updates provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69641 to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-08-03T21:24:59.408Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69641","vendor":"Microsoft"}]
Threat ID: 6aa0451aacd9273b49fa977c
Added to database: 09/08/2026, 17:25:46 UTC
Last enriched: 10/16/2026, 21:26:18 UTC
Last updated: 10/23/2026, 15:10:14 UTC
Views: 85
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