cve-2026-80073

CVE-2026-80073 is an Important Microsoft Office Outlook information disclosure vulnerability addressed in Microsoft's September 24, 2026 security release. According to the tagged discussion, the flaw can expose small portions of heap memory when a user interacts with malicious content, including through Outlook's Preview Pane, affecting supported Microsoft 365 Apps, Office 2019, Office LTSC, and Outlook 2016 installations. Microsoft rates exploitation as less likely and reports no observed exploitation, but the Preview Pane vector gives the patch practical urgency for organizations handling untrusted email. Remediation centers on updating each affected Office or Outlook installation to its specified fixed build.