CVE-2026-40363
HIGHCVSS 8.4/10EPSS 0.38%
Last modified
CVE-2026-40363 is a high-severity vulnerability rated 8.4/10 on the CVSS scale. Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.. EPSS estimates a 0.38% chance of exploitation in the next 30 days.
Description
Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.
Metrics
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | 365 Apps | All versions |
| Microsoft | 365 Copilot | < 16.0.19822.20190 |
| Microsoft | Office | 2016 |
| Microsoft | Office | 2019 |
| Microsoft | Office Long Term Servicing Channel | 2021 |
| Microsoft | Office Long Term Servicing Channel | 2024 |
References
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2026-40363?
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 a CVSS score of 8.4/10 (HIGH severity). The EPSS model estimates a 0.38% probability of exploitation in the next 30 days.
How do I fix CVE-2026-40363?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
Are you affected by CVE-2026-40363?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST