Microsoft Office Outlook
CVE-2026-21260 — Microsoft Outlook Spoofing Vulnerability
Executive Summary
Exposure of sensitive information to an unauthorized actor in Microsoft Office Outlook allows an unauthorized attacker to perform spoofing over a network.
Overview
7.5
CVSS HIGH
Important
MS Severity
Not Exploited
MS Exploit Status
Exploitation Unlikely
MS Exploit Likelihood
CVSS Vector
ATTACK VECTOR
Network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
None
SCOPE
Unchanged
Temporal Score: 6.5
EPSS Score
0.01425
probability of exploitation in the next 30 days
0.69447 percentile - updated 2026-06-20
View on FIRST.org
Affected Products
13 affected products
| Product | KB Article | Severity | Impact | Restart Required |
|---|---|---|---|---|
| Microsoft 365 Apps for Enterprise for 32-bit Systems | Click to Run (Security Update) |
Important | Spoofing | No |
| Microsoft 365 Apps for Enterprise for 64-bit Systems | Click to Run (Security Update) |
Important | Spoofing | No |
| Microsoft Office 2019 for 32-bit editions | Click to Run (Security Update) |
Important | Spoofing | No |
| Microsoft Office 2019 for 64-bit editions | Click to Run (Security Update) |
Important | Spoofing | No |
| Microsoft Office LTSC 2021 for 32-bit editions | Click to Run (Security Update) |
Important | Spoofing | No |
| Microsoft Office LTSC 2021 for 64-bit editions | Click to Run (Security Update) |
Important | Spoofing | No |
| Microsoft Office LTSC 2024 for 32-bit editions | Click to Run (Security Update) |
Important | Spoofing | No |
| Microsoft Office LTSC 2024 for 64-bit editions | Click to Run (Security Update) |
Important | Spoofing | No |
| Microsoft Outlook 2016 (32-bit edition) | 5002839 (Security Update) |
Important | Spoofing | Maybe |
| Microsoft Outlook 2016 (64-bit edition) | 5002839 (Security Update) |
Important | Spoofing | Maybe |
| Microsoft SharePoint Enterprise Server 2016 | 5002841 (Security Update) 5002840 (Security Update) |
Important | Spoofing | Maybe |
| Microsoft SharePoint Server 2019 | 5002834 (Security Update) 5002836 (Security Update) |
Important | Spoofing | Maybe |
| Microsoft SharePoint Server Subscription Edition | 5002833 (Security Update) |
Important | Spoofing | Maybe |
Patches
5 patches
| Article | Type | Restart |
|---|---|---|
Click to Run |
Security Update | No |
5002839 |
Security Update | Maybe |
5002841 (Security Update) 5002840 |
Security Update | Maybe |
5002834 (Security Update) 5002836 |
Security Update | Maybe |
5002833 |
Security Update | Maybe |
Known Exploits
No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.
Acknowledgments
References
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