CVE-2018-0786
HIGHCVE-2018-0786 is a high-severity (CVSS 7.5) CWE-295 vulnerability in Microsoft.NETCore.UniversalWindowsPlatform. O3 Security confirms whether CVE-2018-0786 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Improper Certificate Validation in Microsoft .NET Framework components
Real-World Exposure
Microsoft.NETCore.UniversalWindowsPlatform.NETMicrosoft.NETCore.UniversalWindowsPlatform.NETMicrosoft.NETCore.UniversalWindowsPlatform.NETMicrosoft.NETCore.UniversalWindowsPlatform.NETSystem.ServiceModel.Primitives.NETSystem.ServiceModel.Primitives.NETSystem.ServiceModel.Primitives.NETSystem.ServiceModel.Http+14 moreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.
Description
Microsoft .NET Framework 2.0 SP2, 3.0 SP2, 3.5, 3.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, .NET Core 1.0 and 2.0, and PowerShell Core 6.0.0 allow a security feature bypass vulnerability due to the way certificates are validated, aka ".NET Security Feature Bypass Vulnerability."
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Microsoft.NETCore.UniversalWindowsPlatform | ≥ 5.2.0&&< 5.2.4 | 5.2.4 |
| .NETNuGet | Microsoft.NETCore.UniversalWindowsPlatform | ≥ 5.3.0&&< 5.3.5 | 5.3.5 |
| .NETNuGet | Microsoft.NETCore.UniversalWindowsPlatform | ≥ 5.4.0&&< 5.4.2 | 5.4.2 |
| .NETNuGet | Microsoft.NETCore.UniversalWindowsPlatform | ≥ 6.0.0&&< 6.0.6 | 6.0.6 |
| .NETNuGet | System.ServiceModel.Primitives | ≥ 4.4.0&&< 4.4.1 | 4.4.1 |
| .NETNuGet | System.ServiceModel.Primitives | ≥ 4.3.0&&< 4.3.1 | 4.3.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.NETCore.UniversalWindowsPlatform. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update Microsoft.NETCore.UniversalWindowsPlatform to 5.2.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-0786 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2018-0786 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2018-0786. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2018-0786 in your dependencies?
O3 detects CVE-2018-0786 across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.