CVE-2026-21260

Published: Feb 10, 2026Modified: Jun 17, 2026

7.5

Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Exploitability: 3.9 / Impact: 3.6

Source: secure@microsoft.com (Secondary)

Description

Exposure of sensitive information to an unauthorized actor in Microsoft Office Outlook allows an unauthorized attacker to perform spoofing over a network.

Affected (13)

Products: Microsoft: 365 Apps, Office, Office Long Term Servicing Channel, Outlook, Sharepoint Server

Microsoft

5 products

365 Apps

Office

Office Long Term Servicing Channel

Outlook

Sharepoint Server

Configuration A

13 vulnerable

Vulnerable Software	Affected Versions
Microsoft 365 Apps	All versions
Microsoft 365 Apps	All versions
Microsoft Office	Version 2019
Microsoft Office	Version 2019
Microsoft Office Long Term Servicing Channel	Version 2021
Microsoft Office Long Term Servicing Channel	Version 2021
Microsoft Office Long Term Servicing Channel	Version 2024
Microsoft Office Long Term Servicing Channel	Version 2024
Microsoft Outlook	Version 2016
Microsoft Outlook	Version 2016
Microsoft Sharepoint Server	Before 16.0.19127.20518
Microsoft Sharepoint Server	Version 2016
Microsoft Sharepoint Server	Version 2019

Related CWEs

CWE-200

Exposure of Sensitive Information to an Unauthorized Actor

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

References (1)

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21260

Source: secure@microsoft.com

Vendor Advisory

Timeline

No history available yet.