Vulnerability in Fluent-Plugins-Nursery Fluent-Plugin-Opentelemetry

CVE-2026-44163

fluent-plugin-opentelemetry is a Fluentd input and output plugin for forwarding OpenTelemetry Protocol data. Prior to 0.5.3, the in_opentelemetry HTTP input read the entire incoming request body and decompressed payloads into memory without enforcing maximum size thresholds. When an OpenTelemetry ingestion endpoint was exposed to an untrusted network, an attacker could send an excessively large request or a highly compressed payload that expanded in memory. The resulting memory exhaustion could cause the operating system to terminate the Fluentd process, disrupting all log collection and forwarding on the affected node. This issue is fixed in version 0.5.3.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-44163?
CVE-2026-44163 is a medium-severity vulnerability in Fluent-Plugins-Nursery Fluent-Plugin-Opentelemetry, classified under Improper Handling of Highly Compressed Data (Data Amplification). CVSS score: 5.3/10. Published 2026-09-15.
How severe is CVE-2026-44163?
Medium severity. CVSS v3 base score is 5.3 out of 10.