CVE-2025-27513 is a high-severity (CVSS 7.5) CWE-770 vulnerability in OpenTelemetry.Api. O3 Security confirms whether CVE-2025-27513 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
OpenTelemetry .NET has a Denial of Service (DoS) Vulnerability in API Package
Real-World Exposure
OpenTelemetry.Api.NETOpenTelemetry.Api.NETOpenTelemetry.Api.NETOpenTelemetry.Api.NETOpenTelemetry.ApiReal-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
OpenTelemetry dotnet is a dotnet telemetry framework. A vulnerability in OpenTelemetry.Api package 1.10.0 to 1.11.1 could cause a Denial of Service (DoS) when a tracestate and traceparent header is received. Even if an application does not explicitly use trace context propagation, receiving these headers can still trigger high CPU usage. This issue impacts any application accessible over the web or backend services that process HTTP requests containing a tracestate header. Application may experience excessive resource consumption, leading to increased latency, degraded performance, or downtime. This vulnerability is fixed in 1.11.2.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | OpenTelemetry.Api | ≥ 1.11.0&&< 1.11.2 | 1.11.2 |
| .NETNuGet | OpenTelemetry.Api | all versions | No fix |
| .NETNuGet | OpenTelemetry.Api | all versions | No fix |
| .NETNuGet | OpenTelemetry.Api | all versions | No fix |
| .NETNuGet | OpenTelemetry.Api | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for OpenTelemetry.Api. 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 OpenTelemetry.Api to 1.11.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-27513 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-2025-27513 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-2025-27513. 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-2025-27513 in your dependencies?
O3 detects CVE-2025-27513 across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.