What’s Vulnerable › Vulnerabilities

CVE-2026-44163: fluent-plugin-opentelemetry: Denial of Service (DoS) via Large Payloads and Decompression Bombs in `in_opentelemetry`

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-15 · updated 2026-09-30
• Weakness: CWE-409

Description

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.

Affected products

• fluent-plugins-nursery fluent-plugin-opentelemetry: before 0.5.3

References

• https://github.com/fluent-plugins-nursery/fluent-plugin-opentelemetry/commit/ce6c1f2a7741592c8a79afbe75fded9e8ebfa92d
• https://github.com/fluent-plugins-nursery/fluent-plugin-opentelemetry/security/advisories/GHSA-2jc5-xhx8-qj6h

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