Out-of-bounds read in Microsoft products - CVE-2026-78522

Vulnerability details

The vulnerability allows a remote attacker to disclose sensitive information.

The vulnerability exists due to an out-of-bounds read in Microsoft Office Word when processing crafted content. A remote attacker can provide crafted content to disclose sensitive information.

The Preview Pane is not an attack vector.

Affected software

How to mitigate CVE-2026-78522

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-78522
• https://docs.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Office