Microsoft Exchange Server Remote Code Execution Vulnerability
Conclusion & alert: CVE-2023-21707 is rated High Risk (70.8/100): CVSS High severity, with high exploitation likelihood (EPSS 72.02%, 99th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +1.01% 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 | 2026-03-29 | 71.01% | 72.02% | +1.01% |
| 2 | 2026-02-17 | 73.06% | 71.01% | -2.05% |
| 3 | 2026-02-16 | — | 73.06% | — |
Full EPSS history (33 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 8.8 | 3.1 | HIGH |
|
2.8 | 5.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| microsoft | exchange_server | 2013 | cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_23:*:*:*:*:*:* |
| microsoft | exchange_server | 2016 | cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_23:*:*:*:*:*:* |
| microsoft | exchange_server | 2019 | cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_11:*:*:*:*:*:* |
| microsoft | exchange_server | 2019 | cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_12:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21707 | Patch Vendor Advisory |