CVE-2026-42191
Description
OpenTelemetry.Exporter.OpenTelemetryProtocol is the OTLP (OpenTelemetry Protocol) exporter implementation. From 1.8.0 to 1.15.2, the OTLP disk retry feature in OpenTelemetry.Exporter.OpenTelemetryProtocol silently fell back to Path.GetTempPath() when OTEL_DOTNET_EXPERIMENTAL_OTLP_RETRY=disk was set but OTEL_DOTNET_EXPERIMENTAL_OTLP_DISK_RETRY_DIRECTORY_PATH was not configured. The exporter stored and loaded *.blob files under fixed, signal-named subdirectories (traces, metrics, logs) beneath that shared temporary root path. On multi-user systems where the temporary directory is accessible to other local accounts, this allows an attacker to write crafted *.blob files, read *.blob files written by the application between export failures, or deposit numerous or oversized blob files, degrading retry-loop performance or consuming disk space. This vulnerability is fixed in 1.15.3.
How to fix
- opentelemetry opentelemetry.exporter.opentelemetryprotocol1.15.3 or later
- OpenTelemetry.Exporter.OpenTelemetryProtocol1.15.3 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| opentelemetry opentelemetry.exporter.opentelemetryprotocol | 1.8.0 ≤ v < 1.15.3 | 1.15.3 |
| OpenTelemetry.Exporter.OpenTelemetryProtocolNuGet | 1.8.0 ≤ v < 1.15.3 | 1.15.3 |
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