Microsoft Office Outlook Remote Code Execution Vulnerability
Published September 25, 2026Updated September 25, 2026
Source data
Overview
Integer overflow or wraparound in Microsoft Office Outlook allows an unauthorized attacker to execute code over a network.
Impact & technical details
Remote Code Execution
According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability? Successful exploitation requires an attacker to deliver a specially crafted email containing an unusually large MIME header. The size requirement makes reliable delivery and processing unlikely.
- CVSS base score
- 7.5 / 10
- CVSS vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Highest base score supplied by MSRC for this record; the vector belongs to that score. Ratings can vary by product. Microsoft Important is displayed as High; Moderate is displayed as Medium.
Affected products
- Microsoft 365 Apps for Enterprise for 32-bit Systems
- Microsoft 365 Apps for Enterprise for 64-bit Systems
- Microsoft Office LTSC 2021 for 32-bit editions
- Microsoft Office LTSC 2021 for 64-bit editions
- Microsoft Office LTSC 2024 for 32-bit editions
- Microsoft Office LTSC 2024 for 64-bit editions
Source guidance
Remediation
- Click to Run
Patch availability is not confirmed by this dataset. Consult the vendor before selecting a remediation.
GTP recommendation · Rule-based guidance
Recommended next step
Review affected Microsoft products and apply the applicable security updates through your organization's normal patch-management process. Confirm availability and prerequisites in the Microsoft advisory.
Authoritative sources & updates
Findings and update information come from the linked publishers. GTP compiles the public record and provides the recommendation above. CVSS ratings shown here come from Microsoft. NVD references provide additional public context.
Managed by GTP?
Griffin Technology Partners managed customers may receive additional environment-specific security guidance and remediation assistance through their managed services relationship.
Security bulletins are provided for informational purposes and compiled from authoritative public sources. Vulnerability applicability varies by environment. Validate affected products, configuration, compatibility requirements, and vendor guidance before making production changes.