Stack-based buffer overflow in Microsoft Office - CVE-2026-88156

Vulnerability details

The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to a stack-based buffer overflow in Microsoft Office Outlook when rendering email messages in the Reading Pane. A remote attacker can send a specially crafted email message to a target user to execute arbitrary code.

Exploitation does not require the recipient to open the message, click its contents, or otherwise interact with it.

Affected software

How to mitigate CVE-2026-88156

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-88156
• https://learn.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Office