CVE-2026-81398
Microsoft Excel Remote Code Execution Vulnerability
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Microsoft Excel Remote Code Execution Vulnerability
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- Record
CVE-2026-81398- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - Weakness
- CWE-122
- Updated
- 2026-11-02
EUVDEUVD-2026-73853
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- Record
EUVD-2026-73853- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-x633-79vf-vxw3
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute...
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- Record
GHSA-x633-79vf-vxw3- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-122
- Updated
- 2026-11-02
NVD
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
- Record
CVE-2026-81398- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-122
- Updated
- 2026-11-02
Affected products
- microsoft excel
- microsoft 365 apps
- microsoft 365 apps for enterprise
- microsoft excel 2016
- microsoft office 2016
- microsoft office 2019
- microsoft office 365 for mac
- microsoft office ltsc 2021
- microsoft office ltsc 2024
- microsoft office ltsc for mac 2021
- microsoft office ltsc for mac 2024
- microsoft 365
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History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-81398 is a high vulnerability (CVSS 7.8) in Microsoft Excel, published September 8, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.47%, the 40th percentile. No source names a fixed version.