{"id":"CVE-2026-81871","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-81871","generatedAt":"2026-10-28T04:34:52.892Z","title":"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.","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.","published":"2026-09-16T21:17:22.000Z","lastModified":"2026-09-30T17:31:45.000Z","status":"Awaiting Analysis","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"4.0","score":6.3,"severity":"MEDIUM","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-295","CWE-923"],"affected":[],"epss":{"score":0.00196,"percentile":0.09268,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.20%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/open-telemetry/opentelemetry-go/commit/c65d435b43e5e6b82310e6b18dd4cdcb8ac63a0c","source":"security-advisories@github.com"},{"url":"https://github.com/open-telemetry/opentelemetry-go/releases/tag/exporters/otlp/otlplog/otlploggrpc/v0.21.0","source":"security-advisories@github.com"},{"url":"https://github.com/open-telemetry/opentelemetry-go/security/advisories/GHSA-w34q-cm8f-9c5x","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-81871","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}