How severe is CVE-2024-21413?

CVE-2024-21413 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2024-21413 being actively exploited?

Yes. CVE-2024-21413 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2025-02-06, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2024-21413?

CVE-2024-21413 primarily affects Microsoft 365 Apps. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2024-21413?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2024-21413 have an EU (EUVD) identifier?

Yes. CVE-2024-21413 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-19122. It is also flagged as exploited in the EUVD (since 2025-02-06).

When was CVE-2024-21413 published?

CVE-2024-21413 was published on 2024-02-13 and last updated on 2026-08-10.

CVE-2024-21413

CVE-2024-21413 is a critical-severity vulnerability in Microsoft 365 Apps with a CVSS 3.x base score of 9.8. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2025-02-06). The underlying weakness is classified as CWE-20.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 95% (100th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2025-02-06)
EU (EUVD) id: EUVD-2024-19122
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2025-02-06)
Weakness: CWE-20
Affected product: Microsoft 365 Apps
Published: 2024-02-13
Last modified: 2026-08-10

Description

Microsoft Outlook Remote Code Execution Vulnerability

Frequently asked questions

What is CVE-2024-21413?: Microsoft Outlook Remote Code Execution Vulnerability
How severe is CVE-2024-21413?: CVE-2024-21413 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2024-21413 being actively exploited?: Yes. CVE-2024-21413 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2025-02-06, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2024-21413?: CVE-2024-21413 primarily affects Microsoft 365 Apps. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2024-21413?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2024-21413 have an EU (EUVD) identifier?: Yes. CVE-2024-21413 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-19122. It is also flagged as exploited in the EUVD (since 2025-02-06).
When was CVE-2024-21413 published?: CVE-2024-21413 was published on 2024-02-13 and last updated on 2026-08-10.

References

Affected products (6)

cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:*:*
cpe:2.3:a:microsoft:office_2016:-:*:*:*:-:*:x64:*
cpe:2.3:a:microsoft:office_2016:-:*:*:*:-:*:x86:*
cpe:2.3:a:microsoft:office_2019:-:*:*:*:*:*:x64:*
cpe:2.3:a:microsoft:office_2019:-:*:*:*:*:*:x86:*
cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:*:*:*

More vulnerabilities in Microsoft 365 Apps

CVE-2026-78509 — Critical (CVSS 9.8): Heap-based buffer overflow in Microsoft Office Outlook allows an unauthorized attacker to execute code over a network.
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