CVE-2026-56164

Published Jul 14, 2026

Last updated 2 hours ago

Overview

AI description

Automated description summarized from trusted sources.

CVE-2026-56164 is a missing authentication for critical function vulnerability found in Microsoft SharePoint Server. This flaw allows an unauthorized attacker to elevate privileges over a network. The vulnerability affects all supported on-premises SharePoint Server versions, including Subscription Edition, 2019, and 2016. It has been actively exploited in the wild as a zero-day, enabling cyber threat actors to gain unauthorized access to SharePoint Server instances and potentially engage in post-exploitation activities.

Description
Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network.
Source
secure@microsoft.com
NVD status
Undergoing Analysis

Risk scores

CVSS 3.1

Type
Secondary
Base score
5.3
Impact score
1.4
Exploitability score
3.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Severity
MEDIUM

Known exploits

Data from CISA

Vulnerability name
Microsoft SharePoint Server Missing Authentication for Critical Function Vulnerability
Exploit added on
Jul 14, 2026
Exploit action due
Jul 17, 2026
Required action
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Weaknesses

secure@microsoft.com
CWE-306

Social media

Hype score is a measure of social media activity compared against trending CVEs from the past 12 months. Max score 100.

Hype score

8