Improper authentication in Microsoft Office SharePoint allows an unauthorized attacker to perform spoofing over a network.
Conclusion & alert: CVE-2025-53771 is rated High Risk (66/100): CVSS Medium severity, with high exploitation likelihood (EPSS 99.89%, 100th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +61.45% 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 | 2026-06-15 | 38.44% | 99.89% | +61.45% |
| 2 | 2026-06-08 | 32.16% | 38.44% | +6.28% |
| 3 | 2026-05-30 | — | 32.16% | — |
Full EPSS history (60 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.5 | 3.1 | MEDIUM |
|
3.9 | 2.5 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| microsoft | sharepoint_server | < 16.0.18526.20508 | cpe:2.3:a:microsoft:sharepoint_server:*:*:*:*:subscription:*:*:* |
| microsoft | sharepoint_server | 2016 | cpe:2.3:a:microsoft:sharepoint_server:2016:*:*:*:enterprise:*:*:* |
| microsoft | sharepoint_server | 2019 | cpe:2.3:a:microsoft:sharepoint_server:2019:*:*:*:*:*:*:* |