CVE-2026-40894: opentelemetry — Fix

Description

OpenTelemetry dotnet is a dotnet telemetry framework. In OpenTelemetry.Api 0.5.0-beta.2 to 1.15.2 and OpenTelemetry.Extensions.Propagators 1.3.1 to 1.15.2, The implementation details of the baggage, B3 and Jaeger processing code in the OpenTelemetry.Api and OpenTelemetry.Extensions.Propagators NuGet packages can allocate excessive memory when parsing which could create a potential denial of service (DoS) in the consuming application. This vulnerability is fixed in 1.15.3.

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CVSS v3.1 Score

5.3

MEDIUM

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

EPSS — Exploit Prediction

0.0003

Probability of exploitation

0.08%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-789 CWE-789

Affected Products

Vendor	Product	Versions
opentelemetry	opentelemetry	0.5.0 — 1.15.3
opentelemetry	opentelemetry.api	0.5.0 — 1.15.3
opentelemetry	opentelemetry.extensions.propagators	< 1.15.3

References

Advisories & Patches

https://github.com/open-telemetry/opentelemetry-dotnet/pull/1048 https://github.com/open-telemetry/opentelemetry-dotnet/pull/3244 https://github.com/open-telemetry/opentelemetry-dotnet/pull/3309 https://github.com/open-telemetry/opentelemetry-dotnet/pull/533 https://github.com/open-telemetry/opentelemetry-dotnet/pull/7061 https://github.com/open-telemetry/opentelemetry-dotnet/security/advisories/GHSA-g94r-2vxg-569j

Frequently Asked Questions

What is CVE-2026-40894? +

OpenTelemetry dotnet is a dotnet telemetry framework. In OpenTelemetry.Api 0.5.0-beta.2 to 1.15.2 and OpenTelemetry.Extensions.Propagators 1.3.1 to 1.15.2, The implementation details of the baggage, B3 and Jaeger processing code in the OpenTelemetry.Api and OpenTelemetry.Extensions.Propagators NuGet packages can allocate excessive memory when parsing which could create a potential denial of service (DoS) in the consuming application. This vulnerability is fixed in 1.15.3. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2026-40894? +

CVE-2026-40894 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0003, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-40894? +

CVE-2026-40894 affects products from opentelemetry, specifically: opentelemetry, opentelemetry.api, opentelemetry.extensions.propagators. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-40894? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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