Security Updates for Microsoft Office Products C2R (February 2026)

high Nessus Plugin ID 298977

Synopsis

The Microsoft Office Products are affected by a security feature bypass vulnerability.

Description

The Microsoft Office Products are missing security updates. It is, therefore, affected by a vulnerability:

- A security feature bypass vulnerability. Reliance on untrusted inputs in a security decision in Microsoft Office allows an unauthorized attacker to bypass a security feature locally. (CVE-2026-21509)

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 patches to address these issues.

For Office 365, Office 2016 C2R, or Office 2019, 2021 or 2024, ensure automatic updates are enabled or open any office app and manually perform an update.

Plugin Details

Severity: High

ID: 298977

File Name: smb_nt_ms26_feb_office_c2r.nasl

Version: 1.1

Type: local

Agent: windows

Family: Windows

Published: 2/13/2026

Updated: 2/13/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Critical

Score: 9.5

CVSS v2

Risk Factor: High

Base Score: 7.2

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

CVSS Score Source: CVE-2026-21509

CVSS v3

Risk Factor: High

Base Score: 7.8

Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/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: 2/10/2026

Vulnerability Publication Date: 1/26/2026

Reference Information

CVE: CVE-2026-21509

Detections

Analytics