CVE-2026-81871

MEDIUMPre-NVD 6.36.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 90% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 3 sources updated this week
6.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.3Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
6.3
EG Score
6.3(medium)
EG Risk
28(Track)
EG Risk 28/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity63% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
10%
KEV
Not listed

Published

September 16, 2026

Last Modified

September 17, 2026

Advisory Details (2)

Auto-updated Sep 16, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit.
github_commit

commit c65d435b43e5 (open-telemetry/opentelemetry-go)

Fix landed in open-telemetry/opentelemetry-go commit c65d435b43e5 — awaiting tagged release

https://github.com/open-telemetry/opentelemetry-go/commit/c65d435b43e5e6b82310e6b18dd4cdcb8ac63a0c
github Patch Available🟡 PoC Available

Log gRPC exporter ignores env TLS certs, bypassing mTLS/pinning · Advisory · open-telemetry/opentelemetry-go · GitHub

https://github.com/open-telemetry/opentelemetry-go/security/advisories/GHSA-w34q-cm8f-9c5x

Vendor Advisories for CVE-2026-81871(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc—0.21.0—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 7× in last 7d / 7× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 21:37 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-17 20:28 UTCEG score recompute
  4. 2026-09-17 19:31 UTCEG score recompute
  5. 2026-09-16 21:23 UTCEG score recompute
  6. 2026-09-16 20:52 UTCEG score recompute
  7. 2026-09-16 20:49 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-81871?
CVE-2026-81871 is a medium vulnerability published on September 16, 2026. OpenTelemetry-Go is the Go implementation of OpenTelemetry. Prior to version 0.21.0, the exporters/otlp/otlplog/otlploggrpc package loads OTELEXPORTEROTLPLOGSCERTIFICATE, OTELEXPORTEROTLP_CERTIFICATE, and related client certificate environment variables through loadEnvTLS into cfg.tlsCfg, but…
When was CVE-2026-81871 disclosed?
CVE-2026-81871 was first published in the National Vulnerability Database on September 16, 2026, with the most recent update on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-81871 actively exploited?
CVE-2026-81871 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 90.3% of all scored CVEs.
What is the CVSS score of CVE-2026-81871?
CVE-2026-81871 has a CVSS v3 base score of 6.3 (NVD).
How do I remediate CVE-2026-81871?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-81871, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-81871

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