Buffer over-read in Microsoft products - CVE-2026-83951

Vulnerability details

The vulnerability allows a remote attacker to disclose information.

The vulnerability exists due to a buffer over-read in Microsoft Office Word when opening a malicious Office file. A remote attacker can send a malicious Office file and convince a user to open it to disclose information.

The Preview Pane is not an attack vector.

Affected software

How to mitigate CVE-2026-83951

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-83951
• https://docs.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Office