Microsoft Outlook Security Feature Bypass Vulnerability
What it is
Microsoft Outlook contains a security feature bypass vulnerability that allows an attacker to bypass the Microsoft Outlook Security Notice prompt.
Who's affected
Affects anyone using Outlook as their mail client. In a CPA or legal practice, Outlook is typically how staff send privileged correspondence and exchange documents — credential or session compromise here exposes that.
What to do
Apply updates per vendor instructions or discontinue use of the product if updates are unavailable.
CISA action deadline: August 1, 2023. Federal agencies must complete the required action by this date. For private SMBs the deadline is advisory — but treat it as a strong recommendation, especially if you handle regulated data (HIPAA, GLBA, ABA model rules).
If you don't have someone in-house to verify the patch deployed across every endpoint — or you're not sure whether you're affected — that's exactly the kind of triage we do. Book a free 20-minute triage call.
Severity
CVSS base score: 8.8 — HIGH
Weakness classification: CWE-367
Source
Pulled daily from the public cisagov/kev-data mirror (CC0). View the original entry on cisa.gov. CISA KEV is US-Government public-domain data; we add the SMB-vertical framing and the coping action above.