Vulnerability · Published Oct 13, 2026 · Assigned by microsoft
CVE-2026-97777Microsoft Office Excel Remote Code Execution Vulnerability
High 8.8
In plain English
A high-severity heap buffer overflow in Microsoft 365 Apps for Enterprise from Microsoft. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 58% of all known vulnerabilities).
Severity (CVSS 3.1)8.8High
Exploit odds (30 days)0.8%top 41.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code over a network.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Microsoft 365 Apps for Enterprise | 16.0.1 – before https://aka.ms/OfficeSecurityReleases |
| Microsoft | Microsoft Office 365 for Mac | 1.0.0 – before 16.114.26101123 |
| Microsoft | Microsoft Office LTSC 2021 | 16.0.1 – before 16.0.14334.20974 |
| Microsoft | Microsoft Office LTSC 2024 | 16.0.0 – before 16.0.17932.21056 |
| Microsoft | Microsoft Office LTSC for Mac 2021 | 16.0.1 – before 16.114.26101123 |
| Microsoft | Microsoft Office LTSC for Mac 2024 | 16.0.0 – before 16.114.26101123 |
| Microsoft | Office Online Server | 16.0.0.0 – before 16.0.10417.20228 |
Weakness: CWE-122 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
References
- Microsoft Office Excel Remote Code Execution Vulnerability vendor-advisory, patch