SB2026051368 - Multiple vulnerabilities in Microsoft SharePoint Server

Main Vulnerability Database SB2026051368

SB2026051368 - Multiple vulnerabilities in Microsoft SharePoint Server

Published: May 13, 2026

Security Bulletin ID SB2026051368

CSH Severity

Medium

Patch available

YES

Number of vulnerabilities 6

Exploitation vector Remote access

Highest impact Code execution

Breakdown by Severity

Low
Medium
High
Critical

Description

This security bulletin contains information about 6 vulnerabilities.

1) Insufficient Granularity of Access Control (CVE-ID: CVE-2026-40365)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to insufficient granularity of access control in Microsoft SharePoint Server. A remote user can execute arbitrary code on the system.

2) Deserialization of Untrusted Data (CVE-ID: CVE-2026-40357)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to insecure input validation when processing serialized data in Microsoft SharePoint Server. A remote user can pass specially crafted data to the application and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

3) Deserialization of Untrusted Data (CVE-ID: CVE-2026-33112)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to insecure input validation when processing serialized data in Microsoft SharePoint Server. A remote user can pass specially crafted data to the application and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

4) Deserialization of Untrusted Data (CVE-ID: CVE-2026-33110)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to insecure input validation when processing serialized data in Microsoft SharePoint Server. A remote user can pass specially crafted data to the application and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

5) Deserialization of Untrusted Data (CVE-ID: CVE-2026-35439)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to insecure input validation when processing serialized data in Microsoft SharePoint Server. A remote user can pass specially crafted data to the application and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

6) Deserialization of Untrusted Data (CVE-ID: CVE-2026-40368)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to insecure input validation when processing serialized data in Microsoft SharePoint Server. A remote user can trick a victim to connect to a malicious server and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Remediation

Install update from vendor's website.

References