What is CVE-2021-24066?

CVE-2021-24066 is a high-severity vulnerability in Microsoft Sharepoint Enterprise Server 2016, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2021-02-25.

How severe is CVE-2021-24066?

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

Deserialization in Microsoft Sharepoint Enterprise Server 2016

CVE-2021-24066

Microsoft SharePoint Remote Code Execution Vulnerability

Vulnerability class: Insecure Deserialization

Published 2021-02-25 · last modified 2026-06-17.

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: 0.063 (93.4th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 93rd percentile — 93.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.059 · newest: 0.063 · change: +0.004

Affected products

Microsoft Sharepoint Enterprise Server 2016 — versions 16.0.0
Microsoft Sharepoint Foundation 2010 Service Pack 2 — versions 13.0.0
Microsoft Sharepoint Foundation 2013 Service Pack 1 — versions 15.0.0
Microsoft Sharepoint Server 2019 — versions 16.0.0
Microsoft Sharepoint Enterprise Server — versions 2016
Microsoft Sharepoint Foundation — versions 2010, 2013
Microsoft Sharepoint Server — versions 2019

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-24066 (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-24066?: CVE-2021-24066 is a high-severity vulnerability in Microsoft Sharepoint Enterprise Server 2016, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2021-02-25.
How severe is CVE-2021-24066?: High severity. CVSS v3 base score is 8.8 out of 10.