Out-of-bounds read in Microsoft Office for macOS and Microsoft Office - CVE-2026-56193

Vulnerability details

The vulnerability allows a remote attacker to disclose sensitive information.

The vulnerability exists due to out-of-bounds read in Microsoft Office for macOS when parsing a crafted Office file. A remote attacker can send a specially crafted Office file to disclose sensitive information.

User interaction is required to open or preview the crafted file, and the Preview Pane can be used as an attack vector. The disclosed information is limited to memory-related information, specifically a heap address returned by the affected service.

Affected software

How to mitigate CVE-2026-56193

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-56193
• https://www.microsoft.com/en-us/microsoft-365/mac/microsoft-365-for-mac?msockid=35f9adb0e74b61392038b90de6fe608c

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Office