CVE-2026-81870

Information Disclosure in go.opentelemetry.io/otel/sdk (CVE-2026-81870)

Summary

Vulnerability in go.opentelemetry.io/otel/sdk (CVE-2026-81870). Risk of unauthorized operations or information disclosure. Exploitable via TracerProvider. Mitigation: upgrade to 1.45.0 or later.

Original description

The description as published by the source.

Summary

OpenTelemetry Go versions 1.5.0 through 1.44.0 can include trace exporter endpoint configuration in an internal diagnostic log emitted when an SDK TracerProvider is created. The default OpenTelemetry logger does not emit this event. Exposure requires an application to install a logger that enables OpenTelemetry's internal Info-level diagnostics and for someone other than the intended audience to have access to those logs.

The logged configuration can disclose the address of the trace collector and whether the OTLP/HTTP connection is configured as insecure. The Zipkin exporter logs its complete collector URL, so credentials in URL userinfo or tokens in the query string are also disclosed if an application embeds them there. OTLP authentication headers, TLS key material, and exported span data are not included in this log.

Exporter MarshalLog implementations that caused this configuration to be included in internal logs were introduced by a1fff3c.

Details

When sdk/trace.NewTracerProvider constructs a provider, it records a TracerProvider created internal Info event containing the provider configuration. In affected versions, the configuration's MarshalLog methods recursively include:

the provider's span processors;
each processor's span exporter; and
for the OTLP trace exporter, its client configuration.

This causes the following valu…

Source: NIST National Vulnerability Database NVD GitHub Advisory

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2026-81870 has been found in go.opentelemetry.io/otel/sdk.
Attackers can target a specific entry point like TracerProvider over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade go.opentelemetry.io/otel/sdk to 1.45.0 or later.
If unsure, ask your IT team or search "go.opentelemetry.io/otel/sdk CVE-2026-81870" on the vendor's site.

CVE-2026-81870 (go.opentelemetry.io/otel/sdk) — CWE-200
Attack surface: TracerProvider / MarshalLog / a1fff3c / Insecure
Patched: 1.45.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

Information disclosure (CWE-200) exists in go.opentelemetry.io/otel/sdk. Attackers reach the vulnerable code path via TracerProvider.

📍 Affected scope

Check the vendor advisory for the affected versions of go.opentelemetry.io/otel/sdk. Attack surface: TracerProvider / MarshalLog / a1fff3c / Insecure.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 1.45.0.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'go.opentelemetry.io/otel/sdk' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'go.opentelemetry.io/otel/sdk' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で go.opentelemetry.io/otel/sdk を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade go.opentelemetry.io/otel/sdk to 1.45.0
```
ステージング環境で 1.45.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。