Microsoft Excel Remote Code Execution Vulnerability
Priority LOW 36CWE-122Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from Microsoft.
Summary
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00466 40th percentileScored 2026-11-07
Fix Fixed Microsoft 365 Apps for Enterprise (Microsoft): https://aka.ms/OfficeSecurityReleasesMicrosoft Office 365 for Mac (Microsoft): 16.111.26071215+4 more products
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Microsoft | Microsoft 365 Apps for Enterprise | 16.0.1 to before https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases | Patch available | CNA |
| Microsoft | Microsoft Office 365 for Mac | 1.0.0 to before 16.111.26071215 | 16.111.26071215 | Patch available | CNA |
| Microsoft | Microsoft Office LTSC 2021 | 16.0.1 to before https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases | Patch available | CNA |
| Microsoft | Microsoft Office LTSC 2024 | 16.0.0 to before https://aka.ms/OfficeSecurityReleases | https://aka.ms/OfficeSecurityReleases | Patch available | CNA |
| Microsoft | Microsoft Office LTSC for Mac 2021 | 16.0.1 to before 16.111.26071215 | 16.111.26071215 | Patch available | CNA |
| Microsoft | Microsoft Office LTSC for Mac 2024 | 16.0.0 to before 16.111.26071215 | 16.111.26071215 | 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 Office 365 for Mac VendorMicrosoft Affected 1.0.0 to before 16.111.26071215 Fixed in 16.111.26071215 Patch available CNA
- Microsoft Office LTSC 2021 VendorMicrosoft Affected 16.0.1 to before https://aka.ms/OfficeSecurityReleases Fixed in https://aka.ms/OfficeSecurityReleases Patch available CNA
- Microsoft Office LTSC 2024 VendorMicrosoft Affected 16.0.0 to before https://aka.ms/OfficeSecurityReleases Fixed in https://aka.ms/OfficeSecurityReleases Patch available CNA
- Microsoft Office LTSC for Mac 2021 VendorMicrosoft Affected 16.0.1 to before 16.111.26071215 Fixed in 16.111.26071215 Patch available CNA
- Microsoft Office LTSC for Mac 2024 VendorMicrosoft Affected 16.0.0 to before 16.111.26071215 Fixed in 16.111.26071215 Patch available CNA
CPE configurations NVD · 9
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x86:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:microsoft_365:-:*:*:*:*:macos:*:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x64:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x86:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:macos:-:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x64:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x86:* | not specified by NVD | Vulnerable | Microsoft |
| cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:macos:-:* | not specified by NVD | Vulnerable | Microsoft |
- cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x86:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:microsoft_365:-:*:*:*:*:macos:*:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x64:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x86:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:macos:-:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x64:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x86:* Versions not specified by NVD Vulnerable ·Microsoft
- cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:macos:-:* Versions not specified by NVD Vulnerable ·Microsoft
Remediation
- Fix · CNA Microsoft 365 Apps for Enterprise (Microsoft) Fixed in https://aka.ms/OfficeSecurityReleases
- Fix · CNA Microsoft Office 365 for Mac (Microsoft) Fixed in 16.111.26071215
- Fix · CNA Microsoft Office LTSC 2021 (Microsoft) Fixed in https://aka.ms/OfficeSecurityReleases
- Fix · CNA Microsoft Office LTSC 2024 (Microsoft) Fixed in https://aka.ms/OfficeSecurityReleases
- Fix · CNA Microsoft Office LTSC for Mac 2021 (Microsoft) Fixed in 16.111.26071215
- Fix · CNA Microsoft Office LTSC for Mac 2024 (Microsoft) Fixed in 16.111.26071215
Vendor assessments
Microsoft
Microsoft's page for this CVE →
- Impact
- Information Disclosure
- Exploited
- No
- Publicly disclosed
- No
- Exploitability
- Exploitation Less Likely
| Product | Status | Plan or fix |
|---|---|---|
| Microsoft 365 Apps for Enterprise for 32-bit Systems | Fixed | https · //aka.ms/OfficeSecurityReleases |
| Microsoft 365 Apps for Enterprise for 64-bit Systems | Fixed | https · //aka.ms/OfficeSecurityReleases |
| Microsoft Office 365 for Mac | Fixed | 16.111.26071215 · Security Update |
| Microsoft Office LTSC 2021 for 32-bit editions | Fixed | https · //aka.ms/OfficeSecurityReleases |
| Microsoft Office LTSC 2021 for 64-bit editions | Fixed | https · //aka.ms/OfficeSecurityReleases |
| Microsoft Office LTSC 2024 for 32-bit editions | Fixed | https · //aka.ms/OfficeSecurityReleases |
| Microsoft Office LTSC 2024 for 64-bit editions | Fixed | https · //aka.ms/OfficeSecurityReleases |
| Microsoft Office LTSC for Mac 2021 | Fixed | 16.111.26071215 · Security Update |
| Microsoft Office LTSC for Mac 2024 | Fixed | 16.111.26071215 · Security Update |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-56156
- 2026-10-03 Alias added: GHSA-4v4x-hh7w-55p3
References
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-2026-56156 · CVE Program
- CVE-2026-56156 · NVD
- FIRST EPSS
- GHSA-4v4x-hh7w-55p3 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-56156 · Microsoft Security Update Guide
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences