{"cve":"CVE-2026-81871","nvd":{"published":"2026-09-16T21:17:22.323","modified":"2026-09-30T17:31:44.573","status":"Awaiting Analysis","description":"OpenTelemetry-Go is the Go implementation of OpenTelemetry. Prior to version 0.21.0, the exporters/otlp/otlplog/otlploggrpc package loads OTEL_EXPORTER_OTLP_LOGS_CERTIFICATE, OTEL_EXPORTER_OTLP_CERTIFICATE, and related client certificate environment variables through loadEnvTLS into cfg.tlsCfg, but newGRPCDialOptions does not apply cfg.tlsCfg when creating gRPC transport credentials. The environment-only TLS path instead uses credentials.NewTLS with system roots and no configured client certificate, bypassing intended private CA pinning and mutual TLS unless the application also supplies WithTLSCredentials. A network attacker able to intercept or spoof the collector connection with a system-trusted certificate can read or alter log telemetry. This issue is fixed in version 0.21.0.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","score":6.3},"cvss_v3":null,"cwes":["CWE-295","CWE-923"],"references":["https://github.com/open-telemetry/opentelemetry-go/commit/c65d435b43e5e6b82310e6b18dd4cdcb8ac63a0c","https://github.com/open-telemetry/opentelemetry-go/releases/tag/exporters/otlp/otlplog/otlploggrpc/v0.21.0","https://github.com/open-telemetry/opentelemetry-go/security/advisories/GHSA-w34q-cm8f-9c5x"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:54:41.405518556+00:00"},"epss":{"cve":"CVE-2026-81871","score":0.00196,"percentile":0.09251,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-w34q-cm8f-9c5x","url":"https://osv.dev/vulnerability/GHSA-w34q-cm8f-9c5x","summary":"OpenTelemetry-Go: Log gRPC exporter ignores env TLS certs, bypassing mTLS/pinning","modified":"2026-09-28T17:10:47.470522671Z","packages":[{"ecosystem":"Go","name":"go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc","purl":"pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc","ranges":["<0.21.0"],"fixed":["0.21.0"]}]},{"id":"GO-2026-6508","url":"https://osv.dev/vulnerability/GO-2026-6508","summary":"OpenTelemetry-Go: Log gRPC exporter ignores env TLS certs, bypassing mTLS/pinning in go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc","modified":"2026-09-28T17:00:16.963674731Z","packages":[{"ecosystem":"Go","name":"go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc","purl":"pkg:golang/go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc","ranges":["<0.21.0"],"fixed":["0.21.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}