CVE-2026-110043: Microsoft Office Outlook heap buffer overflow

CVE-2026-110043 · Severity: high · CVSS 8.8 · Published 2026-11-10

Microsoft Office Outlook, an email and calendar application used by millions of enterprises and individuals, contains a heap buffer overflow vulnerability that allows attackers to execute arbitrary code on a user's computer over the network without authentication. An attacker could exploit this by sending a specially crafted email or calendar invite, leading to complete compromise of the affected system.

Technologies: Microsoft Office Outlook. Vendors: Microsoft.

Quick answers

Is CVE-2026-110043 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-110043 being exploited in the wild.
How severe is CVE-2026-110043?
High severity, with a CVSS score of 8.8, published 10 November 2026.
Which products and versions are affected?
Microsoft Office Outlook <UNKNOWN>.
Is there a fix for CVE-2026-110043?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-110043 attacked?
It is attacked over the network, in a web application.
Am I affected by CVE-2026-110043?
Check whether you run Microsoft Office Outlook at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A heap-based buffer overflow exists in Microsoft Office Outlook that can be triggered over the network without requiring user authentication or interaction beyond receiving a malicious message. The vulnerability allows remote code execution with the privileges of the user running Outlook. The attack vector is network-based.

Affected products

  • Microsoft Office Outlook <UNKNOWN>

Timeline

  • 2026-11-10: disclosed

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.