Detections
Analytics
Security Updates for Microsoft Office Online Server (September 2026)
high Nessus Plugin ID 344556
Synopsis
The Microsoft Office Online Server or Office Web Apps installation on the remote host is affected by multiple vulnerabilities.Description
The Microsoft Office Online Server or Office Web Apps installation on the remote host is missing security updates. It is, therefore, affected by multiple vulnerabilities:- Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally. (CVE-2026-81947)
- Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
(CVE-2026-81956)
- Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information locally. (CVE-2026-81390)
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.
Solution
Apply Security Update 5002910See Also
Plugin Details
Severity: High
ID: 344556
File Name: smb_nt_ms26_sep_office_web.nasl
Version: 1.1
Type: Local
Agent: windows
Family: Windows : Microsoft Bulletins
Published: 9/10/2026
Updated: 9/10/2026
Supported Sensors: Nessus Agent, Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 6.9
Percentile: 96.6
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-2026-81947
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_online_server, cpe:/a:microsoft:office_web_apps
Required KB Items: SMB/MS_Bulletin_Checks/Possible
Patch Publication Date: 9/8/2026
Vulnerability Publication Date: 9/8/2026
Reference Information
CVE: CVE-2026-81390, CVE-2026-81401, CVE-2026-81947, CVE-2026-81956