CVE-2026-88156
Critical
Description
Stack-based buffer overflow in Microsoft Office Outlook allows an unauthorized attacker to execute code over a network.
SeverityCritical
CVSS9.8
Exploit probability—
Product
Microsoft 365
PublishedOct 13, 2026
First seenOct 13, 2026
Weakness typeCWE-121CWE-121
How to fix
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| microsoft microsoft_365 | No range specified | — |
| microsoft 365_apps | No range specified | — |
| microsoft office_2021 | No range specified | — |
| microsoft office_2024 | No range specified | — |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
In the Intelligence 360 plan
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.