Fluentd interruption via unbounded HTTP payload expansion
Published Sep 15, 2026 · Updated Sep 15, 2026
Resource exhaustion in fluent-plugin-opentelemetry before 0.5.3 allows remote attackers to interrupt Fluentd via HTTP payloads. The in_opentelemetry HTTP handler reads each complete request body and expands gzip data into memory without compressed or decompressed size limits. Exploitation requires an OpenTelemetry HTTP ingestion endpoint reachable from an untrusted network and can trigger an operating-system out-of-memory kill that stops log collection and forwarding.
Summary
What happened
Resource exhaustion in fluent-plugin-opentelemetry before 0.5.3 allows remote attackers to interrupt Fluentd via HTTP payloads. The in_opentelemetry HTTP handler reads each complete request body and expands gzip data into memory without compressed or decompressed size limits. Exploitation requires an OpenTelemetry HTTP ingestion endpoint reachable from an untrusted network and can trigger an operating-system out-of-memory kill that stops log collection and forwarding.
The record
- CVE
- CVE-2026-44163
- Published
- Sep 15, 2026
- Updated
- Sep 15, 2026
- Vendor
- fluent-plugins-nursery
- Product
- fluent-plugin-opentelemetry
- Classifications
- T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 15, 2026CVE publishedPublication date reported by the CVE source.
- Sep 15, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 0.5.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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