CVE-2026-20963:

Microsoft SharePoint vulnerable to remote code execution via deserialization of untrusted data.

Score
A numerical rating that indicates how dangerous this vulnerability is.

8.8High

Published Date:Jan 13, 2026
CISA KEV Date:*No Data*
Industries Affected:20

Threat Predictions

EPSS Score:1.6
EPSS Percentile:82%

Exploitability

Score:2.8
Attack Vector:NETWORK
Attack Complexity:LOW
Privileges Required:LOW
User Interaction:NONE
Scope:UNCHANGED

Impact

Score:5.9
Confidentiality Impact:HIGH
Integrity Impact:HIGH
Availability Impact:HIGH

Description Preview

Microsoft SharePoint vulnerable to remote code execution via deserialization of untrusted data.

Overview

The vulnerability in Microsoft Office SharePoint stems from improper deserialization of untrusted data, classified as CWE-502. An attacker with low-level privileges can exploit this flaw remotely without user interaction. The attack vector is network-based, with low attack complexity. Successful exploitation could lead to unauthorized code execution, potentially compromising the entire SharePoint environment. The vulnerability affects confidentiality, integrity, and availability, each rated as high impact. Given the widespread use of SharePoint in enterprise environments, this vulnerability presents a substantial risk to organizations using affected versions of the software.

Remediation

To mitigate the risk posed by CVE-2026-20963, organizations should take the following steps: 1) Apply the latest security patches provided by Microsoft as soon as they become available. 2) Implement network segmentation to limit the exposure of SharePoint servers. 3) Enforce the principle of least privilege for SharePoint users and service accounts. 4) Monitor SharePoint servers for unusual activities or unauthorized access attempts. 5) Consider implementing additional security measures such as Web Application Firewalls (WAF) to filter potentially malicious requests. 6) Regularly review and update SharePoint security configurations. 7) Educate users about the risks of handling untrusted data and the importance of following security best practices.