OpenTelemetry.Exporter.OpenTelemetryProtocol: Disk retry default temp path enables local…
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| open-telemetry | opentelemetry-dotnet | 1.8.0 to before 1.15.3 | 1.15.3 | Patch available | CNA |
| — | OpenTelemetry.Exporter.OpenTelemetryProtocol (NuGet) | 1.8.0 to before 1.15.3 | 1.15.3 | Patch available | GHSA-4625-4j76-fww9 |
- opentelemetry-dotnet Vendoropen-telemetry Affected 1.8.0 to before 1.15.3 Fixed in 1.15.3 Patch available CNA
- OpenTelemetry.Exporter.OpenTelemetryProtocol (NuGet) Vendor— Affected 1.8.0 to before 1.15.3 Fixed in 1.15.3 Patch available GHSA-4625-4j76-fww9
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:opentelemetry:opentelemetry.exporter.opentelemetryprotocol:*:*:*:*:*:.net:*:* | 1.8.0 to before 1.15.3 | Vulnerable | open-telemetry |
- cpe:2.3:a:opentelemetry:opentelemetry.exporter.opentelemetryprotocol:*:*:*:*:*:.net:*:* Versions 1.8.0 to before 1.15.3 Vulnerable ·open-telemetry
Remediation
- Fix · CNA opentelemetry-dotnet (open-telemetry) Fixed in 1.15.3
- Fix · GHSA-4625-4j76-fww9 OpenTelemetry.Exporter.OpenTelemetryProtocol (NuGet) Fixed in 1.15.3 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-42191
- 2026-10-03 Alias added: GHSA-4625-4j76-fww9
References
Advisory 2
Sources
- CVE-2026-42191 · CVE Program
- CVE-2026-42191 · NVD
- FIRST EPSS
- GHSA-4625-4j76-fww9 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences