CVE-2026-44162

fluent-plugin-s3: Denial of Service (DoS) via Decompression Bomb in `in_s3`

State
Published
Severity
2.7 Low
Published
Sep 14, 2026
Updated
Sep 14, 2026
Reserved
May 5, 2026

Read the record on cve.org

Description

fluent-plugin-s3 is an Amazon S3 input and output plugin for Fluentd. From 0.7.0 to 1.8.4, the in_s3 input plugin reads the entire decompressed payload of gzip, lzma2, and lzop objects into memory without enforcing a decompression_size_limit. An attacker with permission to upload objects to the monitored S3 bucket can provide a highly compressed object that expands excessively when Fluentd processes it. The resulting memory exhaustion can cause the operating system to terminate the Fluentd process and disrupt all log collection on the affected node. This issue is fixed in version 1.8.5.

Scores

CVSSScoreVectorSource
3.12.7 LowCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:LGitHub_M

Weaknesses

  • CWE-409 Improper Handling of Highly Compressed Data (Data Amplification)

Affected Products

ProductVersions
fluent-plugin-s3fluent
  • >= 0.7.0, < 1.8.5Affected

References

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