OpenTelemetry.Exporter.Instana bypasses TLS certificate validation when a proxy is configured

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-44213: 0.21% estimated exploitation activity in the next 30 days; percentile 10.85 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary 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 INSTANAENDPOINTPROXY 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. Details The Transport.ConfigureBackendClient() method creates an HttpClient instance that completely disables TLS server certificate validation if the INSTANAENDPOINTPROXY is configured with a valid proxy URL with no ability to re-enable it. Impact If the configured proxy is attacker-controlled (or a network attacker MitM the connection), or if it is possible for the process' configuration to be changed to add an attacker-provided value for INSTANAENDPOINTPROXY then all Instana telemetry could be read by an unauthorized party and the service's Instana API key compromised, potentially…

Published by the source

8 May 2026, 20:48 UTC

Last modified by the source

8 Jun 2026, 23:34 UTC

Source last checked

26 Oct 2026, 17:04 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-wfr5-454p-mjc2

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# Patch Next advisory brief: CVE-2026-44213

Advisory: OpenTelemetry.Exporter.Instana bypasses TLS certificate validation when a proxy is configured
IDs: CVE-2026-44213, GHSA-wfr5-454p-mjc2
Record: https://patchnext.com/advisories/cve-2026-44213 (revision 1, source checked 26 Oct 2026, 17:04 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: opentelemetry.exporter.instana 1.1.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet opentelemetry.exporter.instana: affected <= 1.0.7; fixed in 1.1.0

## Suggested inspection (read-only)
- NuGet opentelemetry.exporter.instana: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on opentelemetry.exporter.instana.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-wfr5-454p-mjc2 (GitHub-reviewed advisory GHSA-wfr5-454p-mjc2 lists affected ranges: NuGet opentelemetry.exporter.instana >=0 <=1.0.7)

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