Vulnerability · Published Jun 9, 2026 · Assigned by microsoft
CVE-2026-44820Microsoft Excel Remote Code Execution Vulnerability
High 7.8
In plain English
A high-severity out-of-bounds read 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 0.4% (higher than 31% of all known vulnerabilities).
Severity (CVSS 3.1)7.8High
Exploit odds (30 days)0.4%top 68.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Microsoft 365 Apps for Enterprise | 16.0.1 – before https://aka.ms/OfficeSecurityReleases |
| Microsoft | Microsoft Excel 2016 | 16.0.0.0 – before 16.0.5556.1001 |
| Microsoft | Microsoft Office 2019 | 19.0.0 – before https://aka.ms/OfficeSecurityReleases |
| Microsoft | Microsoft Office 365 for Mac | 1.0.0 – before 16.110.26061317 |
| Microsoft | Microsoft Office LTSC 2021 | 16.0.1 – before https://aka.ms/OfficeSecurityReleases |
| Microsoft | Microsoft Office LTSC 2024 | 16.0.0 – before https://aka.ms/OfficeSecurityReleases |
| Microsoft | Microsoft Office LTSC for Mac 2021 | 16.0.1 – before 16.110.26061317 |
| Microsoft | Microsoft Office LTSC for Mac 2024 | 16.0.0 – before 16.110.26061317 |
| Microsoft | Office Online Server | 16.0.0.0 – before 16.0.10417.20137 |
Weakness: CWE-125 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
References
- Microsoft Excel Remote Code Execution Vulnerability vendor-advisory, patch