dbcve.org
Improper Certificate ValidationWeakness · CWE-295

CVE-2026-44213

MEDIUM · 6.5 CVSS v3.1 Published 2026-05-26
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The OpenTelemetry.Exporter.Instana exports telemetry to Instana backend. Prior to 1.1.0, the OpenTelemetry.Exporter.Instana NuGet package does not validate HTTPS/TLS certificates are valid when sending telemetry to a configured Instana back-end when a proxy is configured using the INSTANA_ENDPOINT_PROXY environment variable. If a network attacker can Man-in-the-Middle (MitM) the proxy connection, all OpenTelemetry telemetry data and the Instana API key are exposed to the attacker. This vulnerability is fixed in 1.1.0.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The OpenTelemetry.Exporter.Instana NuGet package prior to 1.1.0 fails to validate HTTPS/TLS certificates when a proxy is configured via the INSTANA_ENDPOINT_PROXY environment variable. This allows a network attacker performing a Man-in-the-Middle attack to intercept all telemetry data and the Instana API key sent through the proxy.

MitigationUpgrade OpenTelemetry.Exporter.Instana to version 1.1.0 or later. Until then, avoid using the INSTANA_ENDPOINT_PROXY environment variable or ensure the proxy connection is on a trusted network.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify OpenTelemetry.Exporter.Instana package version
    Run 'dotnet list package' in the project directory, or inspect the .csproj/.packages.config file for a reference to OpenTelemetry.Exporter.Instana and note the version number
    Affected if The package is present with a version lower than 1.1.0 (for example, 1.0.0, 1.0.1, etc.)
  2. Check for proxy configuration environment variable
    Inspect the runtime environment variables for INSTANA_ENDPOINT_PROXY; on Windows use 'echo %INSTANA_ENDPOINT_PROXY%', on Linux/macOS use 'echo $INSTANA_ENDPOINT_PROXY'
    Affected if The INSTANA_ENDPOINT_PROXY environment variable is set to a non-empty value pointing to a proxy URL
  3. Verify HTTPS/TLS validation is enforced for proxy connections
    Review the application code or NuGet package release notes to confirm whether the installed version implements proper certificate validation when connecting through a proxy; for version 1.1.0+, check release notes for TLS proxy fix
    Affected if The installed package version is below 1.1.0 AND the INSTANA_ENDPOINT_PROXY environment variable is configured

A user is affected if the OpenTelemetry.Exporter.Instana package version is below 1.1.0 and a proxy is configured via the INSTANA_ENDPOINT_PROXY environment variable, because certificate validation is disabled for proxy connections in vulnerable versions.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade OpenTelemetry.Exporter.Instana to version 1.1.0 or later. Until then, avoid using the INSTANA_ENDPOINT_PROXY environment variable or ensure the proxy connection is on a trusted network.

Recommended fix High confidence

1.1.0

  1. Update the OpenTelemetry.Exporter.Instana NuGet package to version 1.1.0 or later via NuGet package manager: Install-Package OpenTelemetry.Exporter.Instana -Version 1.1.0
  2. Alternatively, update the PackageReference in your .csproj file to specify version 1.1.0 or higher: <PackageReference Include="OpenTelemetry.Exporter.Instana" Version="1.1.0" />
  3. Run dotnet restore to fetch the updated package
  4. Verify the upgrade by checking that the INSTANA_ENDPOINT_PROXY environment variable is still correctly configured if you use a proxy
  5. Test that telemetry is successfully exported to your Instana backend

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,210
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-44213 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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