SB2026051357 - Multiple vulnerabilities in Microsoft Office



SB2026051357 - Multiple vulnerabilities in Microsoft Office

Published: May 13, 2026

Security Bulletin ID SB2026051357
CSH Severity
High
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 75% Low 25%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 vulnerabilities.


1) Use-after-free (CVE-ID: CVE-2026-40358)

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in Microsoft Office. A remote attacker can execute arbitrary code on the target system.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.


2) Heap-based buffer overflow (CVE-ID: CVE-2026-42831)

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

The vulnerability exists due to a boundary error in Microsoft Office. A remote attacker can trick a victim to open a specially crafted Office file, trigger a heap-based buffer overflow and execute arbitrary code on the target system.

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


3) Heap-based buffer overflow (CVE-ID: CVE-2026-40363)

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

The vulnerability exists due to a boundary error in Microsoft Office. A remote attacker can pass specially crafted data to the application, trigger a heap-based buffer overflow and execute arbitrary code on the target system.

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


4) Improper access control (CVE-ID: CVE-2026-42832)

The vulnerability allows a local attacker to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists due to improper access restrictions in Microsoft Office. A local attacker can bypass implemented security restrictions and perform spoofing attack on the system.


Remediation

Install update from vendor's website.