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HIGH · 8.4

CVE-2026-40363

Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.

Vulnerability Description

Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.

CVSS Score

8.4

HIGH

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH

Affected Products

VendorProductVersions
Microsoft365 Apps-
MicrosoftOffice< 16.0.19822.20190
MicrosoftOffice Long Term Servicing Channel2021

Related Weaknesses (CWE)

CWE-122

References

FAQ

What is CVE-2026-40363?

CVE-2026-40363 is a vulnerability with a CVSS score of 8.4 (HIGH). Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.

How severe is CVE-2026-40363?

CVE-2026-40363 has been rated HIGH with a CVSS base score of 8.4/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-40363?

Check the references section above for vendor advisories and patch information. Affected products include: Microsoft 365 Apps, Microsoft Office, Microsoft Office Long Term Servicing Channel.