SChannel in Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, and Windows RT Gold and 8.1 lacks the required extended master-secret binding support to ensure that a server's X.509 certificate is the same during renegotiation as it was before renegotiation, which allows man-in-the-middle attackers to obtain sensitive information or modify TLS session data via a "triple handshake attack," aka "Schannel TLS Triple Handshake Vulnerability."
Conclusion & alert: CVE-2015-6112 is rated Moderate Risk (48.9/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.81%). 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 | 2026-06-15 | 6.69% | 2.81% | -3.88% |
| 2 | 2026-02-17 | 6.98% | 6.69% | -0.29% |
| 3 | 2026-02-03 | — | 6.98% | — |
Full EPSS history (10 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.8 | 2.0 | MEDIUM |
|
8.6 | 4.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| microsoft | windows_7 | — | cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:* |
| microsoft | windows_8 | — | cpe:2.3:o:microsoft:windows_8:-:*:*:*:*:*:*:* |
| microsoft | windows_8.1 | — | cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:* |
| microsoft | windows_rt | — | cpe:2.3:o:microsoft:windows_rt:-:*:*:*:*:*:*:* |
| microsoft | windows_rt_8.1 | — | cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:* |
| microsoft | windows_server_2008 | — | cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:*:* |
| microsoft | windows_server_2008 | r2 | cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:itanium:* |
| microsoft | windows_server_2008 | r2 | cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:* |
| microsoft | windows_server_2012 | — | cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:* |
| microsoft | windows_server_2012 | r2 | cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:* |
| microsoft | windows_vista | — | cpe:2.3:o:microsoft:windows_vista:-:sp2:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| http://www.securitytracker.com/id/1034124 | Third Party Advisory VDB Entry |
| https://docs.microsoft.com/en-us/security-updates/securitybulletins/2015/ms15-121 | Patch Vendor Advisory |