CVE-2026-66805: 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-2026-66805) affects Microsoft SharePoint Enterprise Server 2016 version 16.0.0. It arises from improper deserialization of untrusted data, classified under CWE-502. Exploitation requires an attacker with authorized access and enables remote code execution without user interaction. The CVSS v3.1 base score is 8.8, indicating high impact on confidentiality, integrity, and availability. Microsoft has published an official fix to remediate this vulnerability.
Potential Impact
Successful exploitation allows an authorized attacker to execute arbitrary code remotely on the affected SharePoint server, potentially compromising confidentiality, integrity, and availability of the system.
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-2026-66805 to remediate this vulnerability.
CVE-2026-66805: 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-2026-66805) affects Microsoft SharePoint Enterprise Server 2016 version 16.0.0. It arises from improper deserialization of untrusted data, classified under CWE-502. Exploitation requires an attacker with authorized access and enables remote code execution without user interaction. The CVSS v3.1 base score is 8.8, indicating high impact on confidentiality, integrity, and availability. Microsoft has published an official fix to remediate this vulnerability.
Potential Impact
Successful exploitation allows an authorized attacker to execute arbitrary code remotely on the affected SharePoint server, potentially compromising confidentiality, integrity, and availability of the system.
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-2026-66805 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-2026-66805","vendor":"Microsoft"}]
Threat ID: 6a7b5835bf8831d539156508
Added to database: 08/11/2026, 17:13:25 UTC
Last enriched: 08/11/2026, 18:46:40 UTC
Last updated: 08/12/2026, 00:12:10 UTC
Views: 2
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
External Links
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.