CVE-2024-27086 is a low-severity (CVSS 3.9) CWE-863 vulnerability in Microsoft.Identity.Client. O3 Security confirms whether CVE-2024-27086 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
MSAL.NET applications targeting Xamarin Android and .NET Android (MAUI) susceptible to local denial of service
Real-World Exposure
Microsoft.Identity.Client.NETMicrosoft.Identity.ClientReal-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
The MSAL library enabled acquisition of security tokens to call protected APIs. MSAL.NET applications targeting Xamarin Android and .NET Android (e.g., MAUI) using the library from versions 4.48.0 to 4.60.0 are impacted by a low severity vulnerability.
A malicious application running on a customer Android device can cause local denial of service against applications that were built using MSAL.NET for authentication on the same device (i.e., prevent the user of the legitimate application from logging in) due to incorrect activity export configuration. MSAL.NET version 4.60.1 includes the fix. As a workaround, a developer may explicitly mark the MSAL.NET activity non-exported.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Microsoft.Identity.Client | ≥ 4.48.0&&< 4.59.1 | 4.59.1 |
| .NETNuGet | Microsoft.Identity.Client | ≥ 4.60.0&&< 4.60.3 | 4.60.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.Identity.Client. 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.Identity.Client to 4.59.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-27086 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-2024-27086 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-2024-27086. 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-2024-27086 in your dependencies?
O3 detects CVE-2024-27086 across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.