CVE-2026-83891

Stack-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code over a network.

CVSS v3 8.8 HIGH

8.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83891	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:microsoft:365_apps:-::::enterprise::x64:*
	cpe:2.3:a:microsoft:365_apps:-::::enterprise::x86:*
	cpe:2.3:a:microsoft:microsoft_365:-:::::macos::
	cpe:2.3:a:microsoft:office_2021:-::::ltsc:-:x64:
	cpe:2.3:a:microsoft:office_2021:-::::ltsc:-:x86:
	cpe:2.3:a:microsoft:office_2021:-::::ltsc:macos:-:
	cpe:2.3:a:microsoft:office_2024:-::::ltsc:-:x64:
	cpe:2.3:a:microsoft:office_2024:-::::ltsc:-:x86:
	cpe:2.3:a:microsoft:office_2024:-::::ltsc:macos:-:

History

14 Oct 2026, 20:14

Type	Values Removed	Values Added
CPE		cpe:2.3:a:microsoft:microsoft_365:-:::::macos:: cpe:2.3:a:microsoft:365_apps:-::::enterprise::x86:* cpe:2.3:a:microsoft:office_2024:-::::ltsc:-:x64: cpe:2.3:a:microsoft:office_2024:-::::ltsc:-:x86: cpe:2.3:a:microsoft:365_apps:-::::enterprise::x64:* cpe:2.3:a:microsoft:office_2024:-::::ltsc:macos:-: cpe:2.3:a:microsoft:office_2021:-::::ltsc:macos:-: cpe:2.3:a:microsoft:office_2021:-::::ltsc:-:x64: cpe:2.3:a:microsoft:office_2021:-::::ltsc:-:x86:
First Time		Microsoft 365 Apps Microsoft Microsoft office 2021 Microsoft microsoft 365 Microsoft office 2024
References	~~() https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83891 -~~	() https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83891 - Vendor Advisory

13 Oct 2026, 19:20

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-13 19:20

Updated : 2026-10-15 21:18

NVD link : CVE-2026-83891

Mitre link : CVE-2026-83891

CVE.ORG link : CVE-2026-83891

JSON object : View

Products Affected

microsoft

office_2024
office_2021
365_apps
microsoft_365

CWE

CWE-20

Improper Input Validation

CWE-121

Stack-based Buffer Overflow

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