Vulnerability in Microsoft 365 Apps
CVE-2025-21357
Microsoft Outlook Remote Code Execution Vulnerability
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.7 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (45.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 45.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: -0.000
Affected products
- Microsoft 365 Apps
- Microsoft 365 Apps For Enterprise — versions 16.0.1
- Microsoft Office 2019 — versions 19.0.0
- Microsoft Office Ltsc 2021 — versions 16.0.1
- Microsoft Office Ltsc 2024 — versions 16.0.0
- Microsoft Outlook 2016 — versions 16.0.0.0
- Microsoft Office — versions 2019
- Microsoft Office Long Term Servicing Channel — versions 2021, 2024
- Microsoft Outlook — versions 2016
Weakness classification (CWE)
Public proof-of-concept exploits
References
- msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21357 (vendor-advisory, Patch, patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2025-21357?
- CVE-2025-21357 is a medium-severity vulnerability in Microsoft 365 Apps, classified under Use of Uninitialized Resource. CVSS score: 6.7/10. Published 2025-01-14.
- How severe is CVE-2025-21357?
- Medium severity. CVSS v3 base score is 6.7 out of 10.
- Is CVE-2025-21357 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.