CVE-2026-40182

Description

OpenTelemetry dotnet is a dotnet telemetry framework. From 1.13.1 to before 1.15.2, When exporting telemetry to a back-end/collector over gRPC or HTTP using OpenTelemetry Protocol format (OTLP), if the request results in a unsuccessful request (i.e. HTTP 4xx or 5xx), the response is read into memory with no upper-bound on the number of bytes consumed. This could cause memory exhaustion in the consuming application if the configured back-end/collector endpoint is attacker-controlled (or a network attacker can MitM the connection) and an extremely large body is returned by the response. This vulnerability is fixed in 1.15.2.

CVSS v3.1 Score

5.3

MEDIUM

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

EPSS — Exploit Prediction

0.0005

Probability of exploitation

0.14%

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	1.13.1 — 1.15.2

References

Advisories & Patches

https://github.com/open-telemetry/opentelemetry-dotnet/pull/6564 https://github.com/open-telemetry/opentelemetry-dotnet/pull/7017 https://github.com/open-telemetry/opentelemetry-dotnet/security/advisories/GHSA-q834-8qmm-v933

Other References

https://github.com/open-telemetry/opentelemetry-proto/pull/781

Frequently Asked Questions

What is CVE-2026-40182? +

OpenTelemetry dotnet is a dotnet telemetry framework. From 1.13.1 to before 1.15.2, When exporting telemetry to a back-end/collector over gRPC or HTTP using OpenTelemetry Protocol format (OTLP), if the request results in a unsuccessful request (i.e. HTTP 4xx or 5xx), the response is read into memory with no upper-bound on the number of bytes consumed. This could cause memory exhaustion in the consuming application if the configured back-end/collector endpoint is attacker-controlled (or a network attacker can MitM the connection) and an extremely large body is returned by the response. This vulnerability is fixed in 1.15.2. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2026-40182? +

CVE-2026-40182 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 0.0005, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-40182? +

CVE-2026-40182 affects products from opentelemetry, specifically: opentelemetry. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-40182? +

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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