CVE-2026-66808: CWE-502: Deserialization of Untrusted Data in Microsoft Microsoft SharePoint Enterprise Server 2016
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-66808) affects Microsoft SharePoint Enterprise Server 2016 version 16.0.0. It is caused by improper handling of deserialization of untrusted data, classified under CWE-502. Exploitation requires an attacker with authorized access and can lead to remote code execution with high impact on confidentiality, integrity, and availability. The CVSS v3.1 base score is 8.8, indicating high severity. Microsoft has released an official fix for this vulnerability as documented in their security update guide.
Potential Impact
Successful exploitation allows an authorized attacker to execute arbitrary code remotely on the affected SharePoint server. This can lead to full compromise of the system, including unauthorized access to sensitive data, modification of information, and disruption of service.
Mitigation Recommendations
An official fix is available from Microsoft. Users should apply the security update provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66808 to remediate this vulnerability.
CVE-2026-66808: CWE-502: Deserialization of Untrusted Data in Microsoft Microsoft SharePoint Enterprise Server 2016
Description
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
CVSS v3.1
Score 8.8high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-66808) affects Microsoft SharePoint Enterprise Server 2016 version 16.0.0. It is caused by improper handling of deserialization of untrusted data, classified under CWE-502. Exploitation requires an attacker with authorized access and can lead to remote code execution with high impact on confidentiality, integrity, and availability. The CVSS v3.1 base score is 8.8, indicating high severity. Microsoft has released an official fix for this vulnerability as documented in their security update guide.
Potential Impact
Successful exploitation allows an authorized attacker to execute arbitrary code remotely on the affected SharePoint server. This can lead to full compromise of the system, including unauthorized access to sensitive data, modification of information, and disruption of service.
Mitigation Recommendations
An official fix is available from Microsoft. Users should apply the security update provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66808 to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-07-27T19:02:26.601Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66808","vendor":"Microsoft"}]
Threat ID: 6a7b5835bf8831d539156511
Added to database: 08/11/2026, 17:13:25 UTC
Last enriched: 08/11/2026, 18:46:14 UTC
Last updated: 08/12/2026, 00:12:10 UTC
Views: 2
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