Generation of error message containing sensitive information in Windows Kernel allows an authorized attacker to disclose information locally.
Conclusion & alert: CVE-2026-20838 is rated Low Risk (38.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.63%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
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 | 2026-06-15 | 0.04% | 0.63% | +0.59% |
| 2 | 2026-06-12 | 0.06% | 0.04% | -0.02% |
| 3 | 2026-04-11 | — | 0.06% | — |
Full EPSS history (7 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.5 | 3.1 | MEDIUM |
|
1.8 | 3.6 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| microsoft | windows_11_23h2 | < 10.0.22631.6491 | cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:*:* |
| microsoft | windows_11_24h2 | < 10.0.26100.7623 | cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:*:* |
| microsoft | windows_11_25h2 | < 10.0.26200.7623 | cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:*:* |
| microsoft | windows_server_2022 | < 10.0.20348.4648 | cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:* |
| microsoft | windows_server_2022_23h2 | < 10.0.25398.2092 | cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:* |
| microsoft | windows_server_2025 | < 10.0.26100.32230 | cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20838 | Vendor Advisory |