M365 Change Tracker

← All changes · security · CVE-2026-78520

CVE-2026-78520CriticalMonitor

Microsoft Office Outlook Information Disclosure Vulnerability

Severity Critical  ·  Urgency Monitor

Why it matters: Critical severity (CVSS 6.5)

Remote Code Execution · Critical · CVSS 6.5. Affects: Microsoft Office, Microsoft 365 Apps, Microsoft Office LTSC for Mac, Microsoft Office LTSC, Microsoft Word, Microsoft Office 365 for Mac.

CVSS 6.5Security update published 2026-09-08Applies to Cloud + on-premisesKB5002923NVD

Affected: Microsoft Office, Microsoft 365 Apps, Microsoft Office LTSC for Mac, Microsoft Office LTSC, Microsoft Word, Microsoft Office 365 for Mac

Related changes

Change history

2026-09-08 · First captured by tracker

View at Microsoft →