CVE-2026-64910 Microsoft CVE debrief

Who should care

Defenders responsible for Microsoft Office installations, particularly those using affected versions, should assess exposure and apply patches. IT administrators and security teams should prioritize patching and monitor Office applications for suspicious activity.

Why it matters

CVE-2026-64910 is a High-severity vulnerability in Microsoft Office that allows remote code execution. Defenders should prioritize patching affected versions and monitor for suspicious activity.

• Verify and apply patches for affected Microsoft Office products to prevent local code execution
• Inventory Office installations to identify exposure and prioritize patching
• Monitor Office applications for suspicious activity indicative of exploitation attempts

Technical summary

The vulnerability is caused by an untrusted pointer dereference in Microsoft Office, allowing an unauthorized attacker to execute code locally. Affected products include Microsoft 365 Apps for Enterprise, Microsoft Office 2019, Microsoft Office 365 for Mac, and various Microsoft Office LTSC versions.

Defensive priority

High

Recommended defensive actions

• Review and apply Microsoft patches for affected Office products
• Inventory Office installations to identify exposure
• Monitor Office applications for suspicious activity

Evidence notes

The CVE record and source item provide details on the vulnerability, affected products, and references to vendor advisories. However, there is limited information on exploitation, impact, or remediation beyond vendor patches.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.