OpenTelemetry's Zipkin remote endpoint cache could grow without bounds and increase memory pressureGHSA-88hf-wf7h-7w4m
MEDIUMFix: open-telemetry/opentelemetry-dotnet#7081GHSA-88hf-wf7h-7w4m is a medium-severity (CVSS 5.3) Uncontrolled Resource Consumption vulnerability in OpenTelemetry.Exporter.Zipkin. A fix is available for OpenTelemetry.Exporter.Zipkin — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-88hf-wf7h-7w4m.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
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
Summary
The Zipkin exporter remote endpoint cache accepted unbounded key growth derived from span attributes. In high-cardinality scenarios, this could increase process memory usage over time and degrade availability.
Details
- Introduce a bounded, thread-safe LRU cache for remote endpoints.
- Enforce fixed maximum size to prevent unbounded growth.
Impact
- A process using Zipkin export for client/producer spans could experience avoidable memory growth under sustained unique remote endpoint values.
Resources
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | OpenTelemetry.Exporter.Zipkin | all versions | 1.15.3dotnet add package OpenTelemetry.Exporter.Zipkin --version 1.15.3 |
Affected Products
opentelemetry.exporter.zipkinopentelemetryDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for OpenTelemetry.Exporter.Zipkin, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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 GHSA-88hf-wf7h-7w4m is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Frequently Asked Questions
Is GHSA-88hf-wf7h-7w4m in your dependencies?
Find it across NuGet, including transitive dependencies.