Security Operations
Threat Intelligence
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CVE-2024-21413 โ€” Microsoft Outlook email spoofing + RCE

Microsoft Outlook vulnerability allowing NTLM credential leak and remote code execution via crafted email links (Patch Tuesday February 2024).
CRITICAL CISA KEV ACTIVELY EXPLOITED
Severity & confidence
Source severitycritical
Platform severitycritical
Confidencehigh
Exploitationactively exploited
CVSS9.8
Affected
VendorsMicrosoftmicrosoft
ProductsMicrosoft 365OutlookOffice Outlook
CountriesUSEUNZAUUK
Sectorstechnologybanking
Reporting sources (2)
Microsoft Security Response Center โ€” Update Guide
Open source โ†—
CISA - Known Exploited Vulnerabilities
Open source โ†—
๐ŸŽฏ Why should I care?
  • Affects a country you follow (New Zealand).
  • Affects a technology you watch (Microsoft 365).
  • On the CISA Known Exploited Vulnerabilities list.
  • Credible sources report active exploitation in the wild.
Timeline & provenance
Published2026-08-17T20:07:49
Last updated2026-10-21T04:58:09
Ingested2026-08-18T20:07:49
FreshnessDAILY
Threat typevulnerability
MITRE ATT&CK
T1566
Recommended action
Apply the February 2024 Patch Tuesday update.
Next steps
  1. Identify affected systems in your environment.
  2. Apply the vendor patch or mitigation guidance.
  3. Review logs for indicators described in the advisory.
  4. Follow the affected vendor/product to track updates.
Confidence explanation
Reported by a government or cert-grade source (CISA, NCSC, NVD, ENISA, MSRC).
Source type: vendor ยท Original: Microsoft Security Response Center โ€” Update Guide