CVE-2024-21413
Critical 9.8 Exploited in the wild (KEV)
Confirmed active exploitation — CISA KEV catalog
- Name
- Microsoft Outlook Improper Input Validation Vulnerability
- Added to catalog
- Remediation due date (US federal)
- Required action
- Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Description
Microsoft Outlook Remote Code Execution Vulnerability
Metrics
- CVSS 3.1
-
9.8 (CRITICAL)
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 95% (percentile: 100) as of 2 November 2026
- CWE
- CWE-20
Affected products
microsoft: 365 apps; microsoft: office 2016; microsoft: office 2019; microsoft: office long term servicing channel
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21413 PatchVendor Advisory
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21413 PatchVendor Advisory
- https://www.vicarius.io/vsociety/posts/cve-2024-21413-critical-monikerlink-vuln… Exploit
- https://research.checkpoint.com/2024/the-risks-of-the-monikerlink-bug-in-micros… Technical Description
- https://www.vicarius.io/vsociety/posts/cve-2024-21413-critical-monikerlink-vuln… Mitigation
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024… US Government Resource