CVE-2026-81951CriticalRevised 24 Sep
Microsoft Excel Remote Code Execution Vulnerability
Assessment
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- Severity
- Critical
- CVSS base score
- 7.8CVSS:3.1/
AV:L/ AC:L/ PR:N/ UI:R/ S:U/ C:H/ I:H/ A:H/ E:U/ RL:O/ RC:C - Impact
- Remote Code Execution
- EPSS, next 30 days
- 0.5%Higher than 37.9% of scored CVEs · FIRST model run 26 Sep 2026 · about EPSS
- Exploitability
- Exploitation Less Likely
- Publicly disclosed
- No
- Customer action
- Required: apply the update
- Component
- Microsoft Office Excel
- Weakness
- CWE-122: Heap-based Buffer Overflow
- Issued by
- Microsoft
- Published
- 8 Sep 2026 · September 2026
- Last revised
- 24 Sep 2026Updated an acknowledgement. This is an informational change only.
Updates that fix it
2 KBs| KB | Type | Restart | Applies to | Other CVEs |
|---|---|---|---|---|
| KB5002904 | Security Update | — | Microsoft Office 2016 (32-bit edition), Microsoft Office 2016 (64-bit edition) | All CVEs in KB5002904 |
| KB5002914 | Security Update | — | Microsoft Excel 2016 (32-bit edition), Microsoft Excel 2016 (64-bit edition) | All CVEs in KB5002914 |
Affected products
Microsoft Office15 affected products
- Microsoft 365 Apps for Enterprise for 32-bit Systems
- Microsoft 365 Apps for Enterprise for 64-bit Systems
- Microsoft Excel 2016 (32-bit edition)
- Microsoft Excel 2016 (64-bit edition)
- Microsoft Office 2016 (32-bit edition)
- Microsoft Office 2016 (64-bit edition)
- Microsoft Office 2019 for 32-bit editions
- Microsoft Office 2019 for 64-bit editions
- Microsoft Office 365 for Mac
- Microsoft Office LTSC 2021 for 32-bit editions
- Microsoft Office LTSC 2021 for 64-bit editions
- Microsoft Office LTSC 2024 for 32-bit editions
- Microsoft Office LTSC 2024 for 64-bit editions
- Microsoft Office LTSC for Mac 2021
- Microsoft Office LTSC for Mac 2024