An elevation of privilege vulnerability exists when Microsoft SharePoint Server and Skype for Business Server improperly handle OAuth token validation. An attacker who successfully exploited the vulnerability could bypass authentication and achieve improper access. To exploit this vulnerability, an attacker would need to modify the token. The update addresses the vulnerability by modifying how Microsoft SharePoint Server and Skype for Business Server validate tokens.
Conclusion & alert: CVE-2020-1025 is rated High Risk (74.4/100): CVSS Critical severity, with high exploitation likelihood (EPSS 15.83%, 95th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +2.04% 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 | 2026-05-13 | 13.80% | 15.83% | +2.04% |
| 2 | 2025-10-23 | 12.89% | 13.80% | +0.91% |
| 3 | 2025-09-10 | — | 12.89% | — |
Full EPSS history (22 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] |
| 7.5 | 2.0 | HIGH |
|
10.0 | 6.4 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| microsoft | lync | 2013 | cpe:2.3:a:microsoft:lync:2013:*:*:*:*:*:*:* |
| microsoft | sharepoint_enterprise_server | 2016 | cpe:2.3:a:microsoft:sharepoint_enterprise_server:2016:*:*:*:*:*:*:* |
| microsoft | sharepoint_foundation | 2013 | cpe:2.3:a:microsoft:sharepoint_foundation:2013:sp1:*:*:*:*:*:* |
| microsoft | sharepoint_server | 2019 | cpe:2.3:a:microsoft:sharepoint_server:2019:*:*:*:*:*:*:* |
| microsoft | skype_for_business | 2015 | cpe:2.3:a:microsoft:skype_for_business:2015:cumulative_update_8:*:*:*:*:*:* |
| microsoft | skype_for_business | 2019 | cpe:2.3:a:microsoft:skype_for_business:2019:cumulative_update_2:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1025 | Patch Vendor Advisory |