CVE-2026-21260
HIGHCVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Lifecycle Timeline
2Description
Exposure of sensitive information to an unauthorized actor in Microsoft Office Outlook allows an unauthorized attacker to perform spoofing over a network.
Analysis
Information disclosure in Microsoft Outlook, SharePoint Server, Office, and 365 Apps enables remote attackers to conduct email spoofing attacks without authentication or user interaction. The vulnerability affects multiple Microsoft collaboration products and could allow threat actors to impersonate legitimate senders to compromise organizational security. …
Sign in for full analysis, threat intelligence, and remediation guidance.
Remediation
Within 24 hours: Notify all users of the spoofing risk and establish guidelines for verifying sender authenticity through out-of-band communication; escalate to Microsoft for patch timeline. Within 7 days: Implement email gateway controls to detect and flag anomalous sender patterns; segment critical business processes to require secondary verification for sensitive transactions. …
Sign in for detailed remediation steps.
Priority Score
Share
External POC / Exploit Code
Leaving vuln.today