Vulnerability · Published Sep 8, 2026 · Assigned by microsoft
CVE-2026-78519Microsoft Office Outlook Remote Code Execution Vulnerability
High 8.8
In plain English
A high-severity security flaw 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 57% of all known vulnerabilities).
Severity (CVSS 3.1)8.8High
Exploit odds (30 days)0.8%top 42.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Use of uninitialized resource in Microsoft Office Outlook 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 16.0.20326.20138 |
| Microsoft | Microsoft Office 2019 | 19.0.0 – before 16.0.10417.20207 |
| Microsoft | Microsoft Office LTSC 2021 | 16.0.1 – before 16.0.14334.20906 |
| Microsoft | Microsoft Office LTSC 2024 | 16.0.0 – before 16.0.17932.20976 |
| Microsoft | Microsoft Outlook 2016 | 16.0.0.0 – before 16.0.5569.1000 |
Weakness: CWE-908 · 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 Outlook Remote Code Execution Vulnerability vendor-advisory, patch