Microsoft Exchange Zero-Day: No Patch, Active Exploitation, Major Risk

About this episode

The episode discusses a critical Microsoft Exchange vulnerability that is actively being exploited, detailing its impacts and mitigation strategies.

A newly disclosed Microsoft Exchange vulnerability is actively being exploited in the wild, and there’s still no permanent patch available. In this episode of IT SPARC Cast – CVE of the Week, John and Lou break down CVE-2026-42897, explain how attackers can exploit Outlook Web Access through malicious emails, and discuss why temporary mitigations may not be enough for organizations still running on-prem Exchange. ⸻ 📄 Show Notes 🚨 CVE of the Week: Microsoft Exchange / Outlook Web Access Exploit This week’s episode focuses on CVE-2026-42897 , a high-severity vulnerability affecting: Microsoft Exchange Server 2016 Microsoft Exchange Server 2019 Exchange Subscription Edition The vulnerability is a cross-site scripting (XSS) and spoofing flaw impacting Outlook Web Access (OWA) . ⸻ ⚠️ How the Attack Works Attackers send specially crafted emails that execute malicious JavaScript when opened through Outlook Web Access. Potential impacts include: Session hijacking Browser-based code execution Exchange session theft Spoofing attacks The vulnerability is already being actively exploited in the wild. ⸻ 🌐 Who Is Affected? This impacts on-prem Exchange deployments only . Cloud-hosted…

People in this episode

Host: John Barger

Guest: Lou

Topics covered

• Microsoft Exchange vulnerability
• cybersecurity
• malicious emails
• temporary mitigations
• cross-site scripting
• session hijacking

Keywords

• Microsoft Exchange
• CVE-2026-42897
• Outlook Web Access
• XSS vulnerability
• malicious JavaScript
• session theft
• spoofing attacks

Mentioned in this episode

Organizations: Microsoft

Products: Microsoft Exchange Server 2016, Microsoft Exchange Server 2019, Exchange Subscription Edition

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