Microsoft is aware of a vulnerability in Servicing Stack that has rolled back the fixes for some vulnerabilities affecting Optional Components on Windows 10, version 1507 (initial version released July 2015). This means that an attacker could exploit these previously mitigated vulnerabilities on Windows 10, version 1507 (Windows 10 Enterprise 2015 LTSB and Windows 10 IoT Enterprise 2015 LTSB) systems that have installed the Windows security update released on March 12, 2024—KB5035858 (OS Build 10240.20526) or other updates released until August 2024. All later versions of Windows 10 are not impacted by this vulnerability. This servicing stack vulnerability is addressed by installing the September 2024 Servicing stack update (SSU KB5043936) AND the September 2024 Windows security update (KB5043083), in that order. Note: Windows 10, version 1507 reached the end of support (EOS) on May 9, 2017 for devices running the Pro, Home, Enterprise, Education, and Enterprise IoT editions. Only Windows 10 Enterprise 2015 LTSB and Windows 10 IoT Enterprise 2015 LTSB editions are still under support.
Conclusion & alert: CVE-2024-43491 is rated High Risk (74.8/100): CVSS Critical severity, with high exploitation likelihood (EPSS 18.18%, 95th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +2.31% over the last day, indicating growing attacker interest. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-05-01 | 15.87% | 18.18% | +2.31% |
| 2 | 2026-03-26 | 15.98% | 15.87% | -0.11% |
| 3 | 2026-02-12 | — | 15.98% | — |
Full EPSS history (30 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.8 | 3.1 | CRITICAL |
|
3.9 | 5.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| microsoft | windows_10_1507 | < 10.0.10240.20766 | cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:x64:* |
| microsoft | windows_10_1507 | <= 10.0.10240.20766 | cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:x86:* |
| URL | Tags |
|---|---|
| https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-43491 | Patch Vendor Advisory |