{"id":"CVE-2026-42191","summary":"OpenTelemetry.Exporter.OpenTelemetryProtocol: Disk retry default temp path enables local blob injection for OTLP Exporter","details":"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.","aliases":["GHSA-4625-4j76-fww9"],"modified":"2026-07-08T08:13:13.686408475Z","published":"2026-05-12T19:12:03.221Z","related":["CGA-vj89-pjc5-fvhq"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42191.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-379"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42191.json"},{"type":"ADVISORY","url":"https://github.com/open-telemetry/opentelemetry-dotnet/security/advisories/GHSA-4625-4j76-fww9"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42191"},{"type":"FIX","url":"https://github.com/open-telemetry/opentelemetry-dotnet/pull/7106"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/open-telemetry/opentelemetry-dotnet","events":[{"introduced":"fb74013d644d56f44ef89dd57358947bd9f68345"},{"fixed":"d622e6c7c899527638b53a6b06919859f5752add"}],"database_specific":{"source":["AFFECTED_FIELD","CPE_RANGE"],"extracted_events":[{"introduced":"1.8.0"},{"fixed":"1.15.3"}],"cpe":"cpe:2.3:a:opentelemetry:opentelemetry.exporter.opentelemetryprotocol:*:*:*:*:*:.net:*:*"}}],"versions":["coreunstable-1.15.2-beta.1","core-1.15.2","coreunstable-1.15.1-beta.1","core-1.15.1","coreunstable-1.15.0-beta.1","core-1.15.0","coreunstable-1.14.0-beta.1","core-1.14.0","core-1.14.0-rc.1","coreunstable-1.13.1-beta.1","core-1.13.1","coreunstable-1.13.0-beta.1","core-1.13.0","coreunstable-1.12.0-beta.1","core-1.12.0","coreunstable-1.11.2-beta.1","core-1.11.2","core-1.11.1","coreunstable-1.11.0-beta.1","core-1.11.0","core-1.11.0-rc.1","coreunstable-1.10.0-beta.1","core-1.10.0","core-1.10.0-rc.1","core-1.10.0-beta.1","coreunstable-1.9.0-beta.2","coreunstable-1.9.0-beta.1","core-1.9.0","core-1.9.0-rc.1","coreunstable-1.9.0-alpha.2","coreunstable-1.9.0-alpha.1","core-1.9.0-alpha.1","core-1.8.0","Instrumentation.Http-1.8.1","Instrumentation.AspNetCore-1.8.1","Instrumentation.SqlClient-1.8.0-beta.1","Instrumentation.Http-1.8.0","Instrumentation.GrpcNetClient-1.8.0-beta.1","Instrumentation.AspNetCore-1.8.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42191.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L"}]}