Microsoft Outlook Denial of Service Vulnerability
Priority LOW 38CWE-401Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-401.
Summary
<p>A denial of service vulnerability exists in Microsoft Outlook software when the software fails to properly handle objects in memory. An attacker who successfully exploited the vulnerability could cause a remote denial of service against a system.</p> <p>Exploitation of the vulnerability requires that a specially crafted email be sent to a vulnerable Outlook server.</p> <p>The security update addresses the vulnerability by correcting how Microsoft Outlook handles objects in memory.</p>
Why it matters now
EPSS 0.02968 87th percentileScored 2026-11-07
Fix Fixed Microsoft Office 2019 (Microsoft): https://aka.ms/OfficeSecurityReleasesMicrosoft 365 Apps for Enterprise (Microsoft): https://aka.ms/OfficeSecurityReleases+3 more products
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Microsoft | Microsoft Office 2019 | 19.0.0 to before https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases | Patch available | CNA |
| Microsoft | Microsoft 365 Apps for Enterprise | 16.0.1 to before https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases | Patch available | CNA |
| Microsoft | Microsoft Outlook 2016 | 16.0.0.0 to before publication | publication | Patch available | CNA |
| Microsoft | Microsoft Outlook 2013 Service Pack 1 | 15.0.0.0 to before publication | publication | Patch available | CNA |
| Microsoft | Microsoft Outlook 2010 Service Pack 2 | 13.0.0.0 to before publication | publication | Patch available | CNA |
- Microsoft Office 2019 VendorMicrosoft Affected 19.0.0 to before https://aka.ms/OfficeSecurityReleases Fixed in https://aka.ms/OfficeSecurityReleases Patch available CNA
- Microsoft 365 Apps for Enterprise VendorMicrosoft Affected 16.0.1 to before https://aka.ms/OfficeSecurityReleases Fixed in https://aka.ms/OfficeSecurityReleases Patch available CNA
- Microsoft Outlook 2016 VendorMicrosoft Affected 16.0.0.0 to before publication Fixed in publication Patch available CNA
- Microsoft Outlook 2013 Service Pack 1 VendorMicrosoft Affected 15.0.0.0 to before publication Fixed in publication Patch available CNA
- Microsoft Outlook 2010 Service Pack 2 VendorMicrosoft Affected 13.0.0.0 to before publication Fixed in publication Patch available CNA
CPE configurations NVD · 26
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:*:* | 1607 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_10:1709:*:*:*:*:*:*:* | 1709 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_10:1803:*:*:*:*:*:*:* | 1803 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_10:1809:*:*:*:*:*:*:* | 1809 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_10:1903:*:*:*:*:*:*:* | 1903 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_10:1909:*:*:*:*:*:*:* | 1909 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:*:* | 2004 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Microsoft |
- cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_10:1607:*:*:*:*:*:*:* Versions 1607 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_10:1709:*:*:*:*:*:*:* Versions 1709 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_10:1803:*:*:*:*:*:*:* Versions 1803 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_10:1809:*:*:*:*:*:*:* Versions 1809 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_10:1903:*:*:*:*:*:*:* Versions 1903 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_10:1909:*:*:*:*:*:*:* Versions 1909 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_10:2004:*:*:*:*:*:*:* Versions 2004 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Microsoft
Show 16 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:*:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:* | r2 sp1 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:* | r2 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_server_2016:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_server_2016:1903:*:*:*:*:*:*:* | 1903 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_server_2016:1909:*:*:*:*:*:*:* | 1909 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:* | 2004 | Vulnerable | Microsoft |
| cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:*:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:office:2019:*:*:*:*:-:*:* | 2019 | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:outlook:2010:sp2:*:*:*:*:*:* | 2010 sp2 | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:outlook:2013:sp1:*:*:*:*:*:* | 2013 sp1 | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:outlook:2013:sp1:*:*:rt:*:*:* | 2013 sp1 | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:outlook:2016:*:*:*:*:*:*:* | 2016 | Vulnerable | Microsoft |
- cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:* Versions r2 sp1 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:* Versions r2 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_server_2016:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_server_2016:1903:*:*:*:*:*:*:* Versions 1903 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_server_2016:1909:*:*:*:*:*:*:* Versions 1909 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_server_2016:2004:*:*:*:*:*:*:* Versions 2004 Vulnerable ·Microsoft
- cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:*:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:office:2019:*:*:*:*:-:*:* Versions 2019 Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:outlook:2010:sp2:*:*:*:*:*:* Versions 2010 sp2 Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:outlook:2013:sp1:*:*:*:*:*:* Versions 2013 sp1 Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:outlook:2013:sp1:*:*:rt:*:*:* Versions 2013 sp1 Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:outlook:2016:*:*:*:*:*:*:* Versions 2016 Vulnerable ·Microsoft
Remediation
- Fix · CNA Microsoft Office 2019 (Microsoft) Fixed in https://aka.ms/OfficeSecurityReleases
- Fix · CNA Microsoft 365 Apps for Enterprise (Microsoft) Fixed in https://aka.ms/OfficeSecurityReleases
- Fix · CNA Microsoft Outlook 2016 (Microsoft) Fixed in publication
- Fix · CNA Microsoft Outlook 2013 Service Pack 1 (Microsoft) Fixed in publication
- Fix · CNA Microsoft Outlook 2010 Service Pack 2 (Microsoft) Fixed in publication
Timeline
- 2026-10-02 Threatist record created from CVE-2020-16949
- 2026-10-03 Alias added: GHSA-cvmr-qp3p-228w
More Microsoft 365 Apps vulnerabilities
- TI-2024-14173 Microsoft Outlook Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
- TI-2023-09240 Microsoft Outlook Elevation of Privilege Vulnerability KEVCVSS 3.1CRITICAL 9.8
- TI-2024-25471 Microsoft Project Remote Code Execution Vulnerability KEVCVSS 3.1HIGH 8.8
- TI-2023-17652 Microsoft Outlook Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 8.8
- TI-2026-17368 Microsoft Word Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 7.8
- TI-2026-17363 Microsoft Office Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 7.8
Sources
- CVE-2020-16949 · CVE Program
- CVE-2020-16949 · NVD
- FIRST EPSS
- GHSA-cvmr-qp3p-228w · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences