CVE-2026-40363
Microsoft Office Remote Code Execution Vulnerability
CVE-2026-40363 is a high vulnerability (CVSS 8.4) in Microsoft Office, published May 12, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.38%, the 32nd percentile. No source names a fixed version.
- Severity
- 8.4 HighCVSS 3.1, CVE List
- Exploit chance
- 0.38%EPSS, 32nd percentile
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
- No fix listedNo source names one
Description
Heap-based buffer overflow in Microsoft Office 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
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
Affected products
- microsoft office
- microsoft 365 apps
- microsoft 365 copilot
- microsoft 365 apps for enterprise
- microsoft office 2016
- microsoft office 2019
- microsoft office for android
- microsoft office ltsc 2021
- microsoft office ltsc 2024
- microsoft office ltsc for mac 2021
- microsoft office ltsc for mac 2024
- microsoft office long term servicing channel
What each source reports
CVE List Score used
Microsoft Office Remote Code Execution Vulnerability
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
- Record
CVE-2026-40363- CVSS 3.1
- 8.4 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - Weakness
- CWE-122
- Updated
- 2026-11-02
EUVDEUVD-2026-29645
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
- Record
EUVD-2026-29645- CVSS 3.1
- 8.4 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-wj5j-v4x9-fvq4
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code...
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
- Record
GHSA-wj5j-v4x9-fvq4- CVSS 3.1
- 8.4 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-122
- Updated
- 2026-11-02
NVD
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
- Record
CVE-2026-40363- CVSS 3.1
- 8.4 High
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-122
- Updated
- 2026-11-02
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.