Windows Local Session Manager (LSM) Elevation of Privilege Vulnerability
Conclusion & alert: CVE-2023-21771 is rated Moderate Risk (48.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.39%). Mandatory action: Review affected assets and schedule 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 | 2026-04-07 | 0.46% | 0.39% | -0.07% |
| 2 | 2026-02-16 | 0.26% | 0.46% | +0.21% |
| 3 | 2026-01-13 | — | 0.26% | — |
Full EPSS history (19 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.0 | 3.1 | HIGH |
|
1.0 | 5.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| microsoft | windows_10 | 20h2 | cpe:2.3:o:microsoft:windows_10:20h2:*:*:*:*:*:*:* |
| microsoft | windows_10 | 21h2 | cpe:2.3:o:microsoft:windows_10:21h2:*:*:*:*:*:*:* |
| microsoft | windows_10 | 22h2 | cpe:2.3:o:microsoft:windows_10:22h2:*:*:*:*:*:*:* |
| microsoft | windows_11 | 21h2 | cpe:2.3:o:microsoft:windows_11:21h2:*:*:*:*:*:arm64:* |
| microsoft | windows_11 | 21h2 | cpe:2.3:o:microsoft:windows_11:21h2:*:*:*:*:*:x64:* |
| microsoft | windows_11 | 22h2 | cpe:2.3:o:microsoft:windows_11:22h2:*:*:*:*:*:arm64:* |
| microsoft | windows_11 | 22h2 | cpe:2.3:o:microsoft:windows_11:22h2:*:*:*:*:*:x64:* |
| microsoft | windows_server_2022 | — | cpe:2.3:o:microsoft:windows_server_2022:-:*:*:*:*:*:*:* |