---
title: "CVE-2026-20963: Microsoft SharePoint Remote Code… | CubePath"
description: "Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network."
language: en
source: https://cubepath.com/security/cve/CVE-2026-20963
---

# CVE-2026-20963: Microsoft SharePoint Remote Code… | CubePath

## Description

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

Official description from the CVE record, published by microsoft. Copyright © 1999-2026 The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CVE license. [View the record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-20963)

## Key data

### CVSS 3.1 Critical 9.8

Score published by microsoft in the CVE record.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

| Metric                 | Value     | What it means                                                                       |
| ---------------------- | --------- | ----------------------------------------------------------------------------------- |
| Attack vector          | Network   | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity      | Low       | No special conditions are needed. The attack can be repeated at will.               |
| Privileges required    | None      | No account or privileges are needed.                                                |
| User interaction       | None      | No action from any user is needed.                                                  |
| Scope                  | Unchanged | The impact stays within the vulnerable component.                                   |
| Confidentiality impact | High      | Serious or total effect on the secrecy of data.                                     |
| Integrity impact       | High      | Serious or total effect on the trustworthiness of data.                             |
| Availability impact    | High      | Serious or total effect on availability.                                            |

CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at [first.org/cvss](https://www.first.org/cvss/) .

### EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.

Score

0.29201 (29.2% probability)

Percentile

98.2%

Scores of

Nov 10, 2026

Model

v2026.06.15

### CISA Known Exploited Vulnerabilities

This CVE is listed in the CISA KEV catalog.

Name in the catalog

Microsoft SharePoint Deserialization of Untrusted Data Vulnerability

Added to the catalog

Mar 18, 2026

Federal due date

Mar 21, 2026

### CISA assessment as of Jan 8, 2026

Stakeholder-Specific Vulnerability Categorization (SSVC) decision points added by CISA.

Exploitation

Recorded by CISA as active

Automatable

yes

Technical impact

total

### Weakness (CWE)

CWE catalog version 5.0.

CWE names: Copyright © 2006-2026, The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CWE license.

- [CWE-502](https://cwe.mitre.org/data/definitions/502.html) Deserialization of Untrusted Data

## Affected products

Products listed in the CVE record, as the CNA published them.

- Microsoft SharePoint Enterprise Server 2016

  - affected: 16.0.0 up to before 16.0.5535.1001
- Microsoft SharePoint Server 2019

  - affected: 16.0.0 up to before 16.0.10417.20083
- Microsoft SharePoint Server Subscription Edition

  - affected: 16.0.0 up to before 16.0.19127.20442

## References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

- [Microsoft SharePoint Remote Code Execution Vulnerability](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20963)  (msrc.microsoft.com) vendor-advisory patch

## Timeline

1. ID reserved Dec 4, 2025
2. Record published Jan 13, 2026
3. Added to CISA KEV Mar 18, 2026
4. Record last updated Jul 30, 2026

## Look up another CVE

## About CubePath

CubePath is a cloud provider with data centers in Europe and the United States. It offers VPS, bare metal servers and DDoS protection.

[Cloud VPS](https://cubepath.com/vps) [DDoS protection](https://cubepath.com/ddos-protection)

Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:12 UTC. [Sources and licenses](https://cubepath.com/security/cve/legal)