What is CVE-2026-35439?

CVE-2026-35439 is a high-severity vulnerability in Microsoft Sharepoint Enterprise Server 2016, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2026-05-12.

How severe is CVE-2026-35439?

High severity. CVSS v3 base score is 8.8 out of 10.

Deserialization in Microsoft Sharepoint Enterprise Server 2016

CVE-2026-35439

Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.

Vulnerability class: Insecure Deserialization

EPSS: 0.008 (74.9th percentile) — read the EPSS interpretation.

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.

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)

CWE-502 — Deserialization of Untrusted Data

References

Microsoft SharePoint Server Remote Code Execution Vulnerability (vendor-advisory, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-35439?: CVE-2026-35439 is a high-severity vulnerability in Microsoft Sharepoint Enterprise Server 2016, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2026-05-12.
How severe is CVE-2026-35439?: High severity. CVSS v3 base score is 8.8 out of 10.