9.8

CVE-2024-21413: Microsoft Outlook Improper Input Validation Vulnerability

CVSS: 9.8v3.1CriticalKEVAnalyzed
Published 13-02-2024Last modified 10-08-2026
Open JSON

Vulnerability summary

CVE-2024-21413 is a critical (CVSS 9.8) Improper Input Validation vulnerability in Microsoft Office Outlook. It is known to be exploited: CISA lists it, first on 06-02-2025. EPSS estimates a 94.66% chance of exploitation in the next 30 days, higher than 99.8% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
85/100
0100
Critical · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
94.66%
0%100%
Critical · 0.00 pp in 30 days
KEVListedCISA
RansomwareNone recordedNo known use recorded
Public exploits1reference

Timeline

  1. 13-02-2024
    PublishedVulnerability first disclosed.
  2. 06-02-2025
    Added to CISA KEVMicrosoft Outlook Improper Input Validation Vulnerability
  3. 27-02-2025
    CISA remediation dueApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
  4. 10-08-2026
    Last modifiedVulnerability information updated.

Description

Microsoft Outlook Remote Code Execution Vulnerability

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

94.66%

Chance of exploitation in the next 30 days

Percentile

100%

Versus all other CVEs

30-day change

0.00 pp

From 94.66% on 20-09-2026

20-09-202620-10-2026
EPSS score
94.66%

Known exploited

Compare KEV catalogs
CISA KEVListed
Added
06-02-2025
Federal due date
27-02-2025

CISA required action

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. msrc.microsoft.com/update-guide/vulnerability/CVE-2024-21413 nvd.nist.gov/vuln/detail/CVE-2024-21413

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (vicarius.io)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Microsoft8 products

1 vendor · 8 products

References

5 links