Buffer over-read in Microsoft Office for macOS and Microsoft Office - CVE-2026-124233

Vulnerability details

The vulnerability allows a remote attacker to disclose information from small portions of heap memory.

The vulnerability exists due to a buffer over-read in Microsoft Office Word when processing a malicious Office file. A remote attacker can send a specially crafted Office file to a user and convince them to open it to disclose information from heap memory.

The Preview Pane is not an attack vector.

Affected software

How to mitigate CVE-2026-124233

External References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-124233
• https://learn.microsoft.com/en-us/officeupdates/release-notes-office-for-mac

Related Security Bulletins

• Multiple vulnerabilities in Microsoft Office