CVE-2026-110043: Microsoft Office Outlook Remote Code Execution Vulnerability
CVE-2026-110043 is a remote code execution vulnerability in Microsoft Office Outlook, rated Critical by Microsoft, with a CVSS 3.1 base score of 8.8 (High). An attacker can exploit it remotely over the network, without any privileges and only if a user takes an action. Microsoft has not reported exploitation in the wild and rates exploitation as less likely. Microsoft released the fix on 10 November 2026 in the November 2026 Patch Tuesday. It affects 6 products in 1 product family (Microsoft Office).
Key facts
- CVE ID
- CVE-2026-110043
- Severity
- High CVSS 8.8
- Microsoft severity
- Critical
- Impact
- Remote Code Execution
- Exploited in the wild
- No
- Publicly disclosed
- No
- Exploitation likelihood
- Less Likely
- Weakness
- CWE-122
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- November 2026 Patch Tuesday
- Product families
- Microsoft Office
CVSS score and vector
Microsoft scores CVE-2026-110043 at 8.8 (temporal 7.7) using CVSS 3.1. 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
| Metric | Value |
|---|---|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | Required |
| Scope | Unchanged |
| Confidentiality impact | High |
| Integrity impact | High |
| Availability impact | High |
| Exploit code maturity | Unproven |
| Remediation level | Official fix |
| Report confidence | Confirmed |
Description
Heap-based buffer overflow in Microsoft Office Outlook allows an unauthorized attacker to execute code over a network.
Frequently asked questions (Microsoft)
How could an attacker exploit this vulnerability?
An attacker could provide a specially crafted email message and convince a user to select it for display in the Outlook Preview Pane. Successful exploitation could allow the attacker to execute code with the user's permissions. The attacker does not need an account on the affected system.
Is the Preview Pane an attack vector for this vulnerability?
Yes, the Preview Pane is an attack vector.
Affected products (6)
Microsoft Office
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| Microsoft Office LTSC 2021 for 64-bit editions | Release Notes | Security Update | 16.0.14334.21048 | |
| Microsoft Office LTSC 2021 for 32-bit editions | Release Notes | Security Update | 16.0.14334.21048 | |
| Microsoft Office LTSC 2024 for 64-bit editions | Release Notes | Security Update | 16.0.17932.21140 | |
| Microsoft Office LTSC 2024 for 32-bit editions | Release Notes | Security Update | 16.0.17932.21140 | |
| Microsoft 365 Apps for Enterprise for 64-bit Systems | Release Notes | Security Update | https://aka.ms/OfficeSecurityReleases | |
| Microsoft 365 Apps for Enterprise for 32-bit Systems | Release Notes | Security Update | https://aka.ms/OfficeSecurityReleases |
NIST NVD data
- NVD status
- Awaiting Analysis
- NVD CVSS
- 8.8 (HIGH)
- NVD weakness
- CWE-122
- Published to NVD
- NVD last modified
References
Acknowledgments
- 0ccbbf129444eb66344ccafb92b00df4
- tiebuchen
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. |