Out-of-bounds read in Microsoft Office for macOS and Microsoft Word - CVE-2026-64917

Vulnerability details

The vulnerability allows a remote attacker to disclose sensitive information.

The vulnerability exists due to out-of-bounds read in Microsoft Office Word when parsing a crafted Office file. A remote attacker can send a specially crafted file and convince the victim to open it to disclose sensitive information.

User interaction is required to open a crafted file, and the Preview Pane is not an attack vector.

Affected software

How to mitigate CVE-2026-64917

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-64917
• https://docs.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Office