CVE-2026-80073 Microsoft CVE debrief

Who should care

Defenders responsible for Microsoft Office and Outlook deployments should assess exposure and prioritize patching affected versions. They should also review and update inventory of Microsoft Office and Outlook deployments, and monitor for potential information disclosure attempts. This includes verifying and applying patches for affected versions, as well as reviewing compensating controls for exposed systems while

Why it matters

CVE-2026-80073 is a medium-severity vulnerability in Microsoft Office Outlook that allows unauthorized information disclosure. Defenders should prioritize patching affected versions and monitoring for potential disclosure attempts.

• Potential information disclosure over the network
• Need to verify and apply patches for affected versions
• Monitoring for potential information disclosure attempts

Technical summary

The vulnerability is caused by an out-of-bounds read in Microsoft Office Outlook, allowing an unauthorized attacker to disclose information over a network. This out-of-bounds read occurs in the affected versions of Microsoft Office and Outlook, which defenders should prioritize verifying and applying patches for. Monitoring for potential information disclosure attempts is also recommended.

Defensive priority

Defenders should prioritize verifying and applying patches for affected Microsoft Office and Outlook versions, as well as monitoring for potential information disclosure attempts.

Recommended defensive actions

• Verify and apply patches for affected Microsoft Office and Outlook versions
• Monitor for potential information disclosure attempts
• Review and update inventory of Microsoft Office and Outlook deployments

Evidence notes

The CVE record and source item provide details on the vulnerability, affected products, and versions. However, there is limited information on exploitation or impact.

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.