CVE-2026-50273
HIGHDatadog .NET Tracer: Improper parsing of W3C baggage headers may lead to DoS
Blast Radius
Datadog.Trace.NETDatadog.Trace.OpenTracingReal-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
Datadog .NET Tracer is a client library for Datadog APM for .NET applications. Prior to 3.43.0, Datadog tracing libraries that implement W3C baggage propagation parse incoming baggage HTTP headers without enforcing DD_TRACE_BAGGAGE_MAX_ITEMS or DD_TRACE_BAGGAGE_MAX_BYTES on extraction, allowing a remote unauthenticated attacker to send a baggage header with many comma-separated key-value pairs or one very large value and cause unbounded CPU and memory consumption in services with baggage propagation enabled. This issue is fixed in version 3.43.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Datadog.Trace | all versions | 3.43.0 |
| .NETNuGet | Datadog.Trace.OpenTracing | all versions | 3.43.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Datadog.Trace. 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 Datadog.Trace to 3.43.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-50273 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-2026-50273 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-2026-50273. 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-2026-50273 in your dependencies?
O3 detects CVE-2026-50273 across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.