Service interruption via unbounded in-memory decompression
Published Sep 14, 2026 · Updated Sep 14, 2026
Resource exhaustion in Fluentd fluent-plugin-s3 0.7.0 through 1.8.4 allows remote authenticated users to crash Fluentd via S3 objects. The in_s3 extractors append each decompressed gzip, lzma2, or lzop chunk to an in-memory string without enforcing a size limit. Exploitation requires permission to upload an object to the monitored S3 bucket; excessive expansion can trigger an operating-system out-of-memory kill and interrupt all log collection on the node.
Summary
What happened
Resource exhaustion in Fluentd fluent-plugin-s3 0.7.0 through 1.8.4 allows remote authenticated users to crash Fluentd via S3 objects. The in_s3 extractors append each decompressed gzip, lzma2, or lzop chunk to an in-memory string without enforcing a size limit. Exploitation requires permission to upload an object to the monitored S3 bucket; excessive expansion can trigger an operating-system out-of-memory kill and interrupt all log collection on the node.
The record
- CVE
- CVE-2026-44162
- Published
- Sep 14, 2026
- Updated
- Sep 14, 2026
- Vendor
- Fluentd
- Product
- fluent-plugin-s3
- Classifications
- CWE-770, T1499.003
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 14, 2026CVE publishedPublication date reported by the CVE source.
- Sep 14, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 0.7.0, < 1.8.5
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo