Vulnerability in Open-Telemetry Opentelemetry-Dotnet-Contrib

CVE-2026-44213

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.

Vulnerability class: Improper Certificate Validation

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.002 (14.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 14.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-44213: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-44213?
CVE-2026-44213 is a medium-severity vulnerability in Open-Telemetry Opentelemetry-Dotnet-Contrib, classified under Improper Certificate Validation. CVSS score: 6.5/10. Published 2026-05-26.
How severe is CVE-2026-44213?
Medium severity. CVSS v3 base score is 6.5 out of 10.