Deserialization in Microsoft Sharepoint Enterprise Server 2016
CVE-2026-66808
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
Vulnerability class: Insecure Deserialization
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.020 (80.4th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 80th percentile — 80.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.011 · newest: 0.020 · change: +0.009
Affected products
- Microsoft Sharepoint Enterprise Server 2016 — versions 16.0.0
- Microsoft Sharepoint Server 2019 — versions 16.0.0
- Microsoft Sharepoint Server Subscription Edition — versions 16.0.0
- Microsoft Sharepoint Server — versions 2016, 2019
Weakness classification (CWE)
References
- Microsoft SharePoint Server Remote Code Execution Vulnerability (vendor-advisory, Patch, patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-66808?
- CVE-2026-66808 is a high-severity vulnerability in Microsoft Sharepoint Enterprise Server 2016, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2026-08-11.
- How severe is CVE-2026-66808?
- High severity. CVSS v3 base score is 8.8 out of 10.