CVE-2025-64666: CWE-20: Improper Input Validation in Microsoft Microsoft Exchange Server 2016 Cumulative Update 23
Improper input validation in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
AI Analysis
Technical Summary
This vulnerability (CVE-2025-64666) in Microsoft Exchange Server 2016 CU23 arises from improper input validation (CWE-20). An attacker with authorized access and low privileges can exploit this flaw remotely to elevate their privileges, potentially gaining higher-level access. The CVSS 3.1 vector indicates network attack vector, high attack complexity, low privileges required, no user interaction, unchanged scope, and high impact on confidentiality, integrity, and availability. The vendor has released a patch to remediate this vulnerability.
Potential Impact
Successful exploitation allows an authorized attacker to elevate privileges on the affected Microsoft Exchange Server 2016 CU23 system remotely. This can lead to full compromise of the server, impacting confidentiality, integrity, and availability of data and services hosted on the server. No known exploits are currently reported in the wild.
Mitigation Recommendations
A patch is available for this vulnerability. It is recommended to apply the official Microsoft update for Exchange Server 2016 Cumulative Update 23 to remediate this issue. Since this is not a cloud service, administrators must manually deploy the patch. No additional vendor advisory content contradicts this guidance.
CVE-2025-64666: CWE-20: Improper Input Validation in Microsoft Microsoft Exchange Server 2016 Cumulative Update 23
Description
Improper input validation in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2025-64666) in Microsoft Exchange Server 2016 CU23 arises from improper input validation (CWE-20). An attacker with authorized access and low privileges can exploit this flaw remotely to elevate their privileges, potentially gaining higher-level access. The CVSS 3.1 vector indicates network attack vector, high attack complexity, low privileges required, no user interaction, unchanged scope, and high impact on confidentiality, integrity, and availability. The vendor has released a patch to remediate this vulnerability.
Potential Impact
Successful exploitation allows an authorized attacker to elevate privileges on the affected Microsoft Exchange Server 2016 CU23 system remotely. This can lead to full compromise of the server, impacting confidentiality, integrity, and availability of data and services hosted on the server. No known exploits are currently reported in the wild.
Mitigation Recommendations
A patch is available for this vulnerability. It is recommended to apply the official Microsoft update for Exchange Server 2016 Cumulative Update 23 to remediate this issue. Since this is not a cloud service, administrators must manually deploy the patch. No additional vendor advisory content contradicts this guidance.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2025-11-06T23:40:37.276Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 693867eb74ebaa3babafb7e1
Added to database: 12/9/2025, 6:18:19 PM
Last enriched: 4/17/2026, 11:17:32 AM
Last updated: 5/7/2026, 7:43:44 AM
Views: 146
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