CVE-2026-41310
MEDIUMCVE-2026-41310 is a medium-severity (CVSS 5.3) vulnerability in OpenTelemetry.Exporter.Zipkin. O3 Security confirms whether CVE-2026-41310 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
OpenTelemetry .NET Zipkin exporter has unbounded remote endpoint cache leading to memory growth
Blast Radius
OpenTelemetry.Exporter.ZipkinReal-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.Exporter.Zipkin is the .NET Zipkin exporter for OpenTelemetry. In versions 1.15.2 and earlier, the Zipkin exporter remote endpoint cache accepts unbounded key growth derived from span attributes. In high-cardinality scenarios, a process using Zipkin export for client or producer spans could experience avoidable memory growth under sustained unique remote endpoint values, increasing process memory usage over time and degrading availability. This issue is fixed in version 1.15.3, which introduces a bounded, thread-safe LRU cache for remote endpoints with a fixed maximum size.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | OpenTelemetry.Exporter.Zipkin | all versions | 1.15.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for OpenTelemetry.Exporter.Zipkin. 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.Exporter.Zipkin to 1.15.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-41310 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-2026-41310 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-2026-41310. 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-2026-41310 in your dependencies?
O3 detects CVE-2026-41310 across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.