Security Updates for Microsoft Office Products (May 2026)

high Nessus Plugin ID 314350

Synopsis

The Microsoft Office Products are affected by multiple remote code execution vulnerabilities.

Description

The Microsoft Office Products are missing a security update. They are, therefore, affected by multiple vulnerabilities:

- Use after free in Microsoft Office allows an unauthorized attacker to execute code locally.
(CVE-2026-40358)

- Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally. (CVE-2026-40363)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Microsoft has released KB5002866 to address this issue.

Plugin Details

Severity: High

ID: 314350

File Name: smb_nt_ms26_may_office.nasl

Version: 1.1

Type: Local

Agent: windows

Family: Windows : Microsoft Bulletins

Published: 5/12/2026

Updated: 5/12/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

CVSS v2

Risk Factor: Critical

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-40358

CVSS v3

Risk Factor: High

Base Score: 8.4

Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Vulnerability Information

CPE: cpe:/a:microsoft:office

Required KB Items: SMB/MS_Bulletin_Checks/Possible

Patch Publication Date: 5/12/2026

Vulnerability Publication Date: 5/12/2026

Reference Information

CVE: CVE-2026-40358, CVE-2026-40363

MSFT: MS26-5002866

MSKB: 5002866

Detections

Analytics