GHSA-xv9w-7v6q-hpjh: fluent-plugin-s3 Vulnerable to Denial of Service (DoS) via Decompression Bomb in `in_s3`
The fluent-plugin-s3's in_s3 input plugin decompresses files from Amazon S3 without enforcing strict size limits on the decompressed payload. This allows an attacker with write permissions to upload a maliciously crafted compressed file that expands excessively in memory, causing a denial of service via memory exhaustion. The vulnerability can lead to the Fluentd process being killed by the operating system, disrupting log collection. A fixed version 1.8.5 is available. Until upgraded, strict IAM controls on S3 bucket write access can mitigate the risk.
AI Analysis
Technical Summary
The fluent-plugin-s3 plugin's in_s3 input reads and decompresses files from S3, including gzip, lzma2, and lzop formats. It does not limit the size of the decompressed data, allowing an attacker with sufficient permissions to upload a highly compressed file that decompresses to a very large size. This causes excessive memory consumption, potentially leading to an out-of-memory kill of the Fluentd process and resulting in denial of service. The vulnerability is tracked as CVE-2026-44162 and fixed in version 1.8.5.
Potential Impact
An attacker with write access to the monitored S3 bucket can cause Fluentd to consume excessive memory during decompression, leading to process termination by the OS and disruption of log collection on the affected node. There is no impact on confidentiality or integrity, only availability (denial of service).
Mitigation Recommendations
Upgrade fluent-plugin-s3 to version 1.8.5 or later, where this issue is fixed. If immediate upgrade is not possible, restrict write (PUT) permissions to the S3 bucket to trusted entities only, preventing untrusted or public uploads that could trigger the vulnerability.
GHSA-xv9w-7v6q-hpjh: fluent-plugin-s3 Vulnerable to Denial of Service (DoS) via Decompression Bomb in `in_s3`
Description
The fluent-plugin-s3's in_s3 input plugin decompresses files from Amazon S3 without enforcing strict size limits on the decompressed payload. This allows an attacker with write permissions to upload a maliciously crafted compressed file that expands excessively in memory, causing a denial of service via memory exhaustion. The vulnerability can lead to the Fluentd process being killed by the operating system, disrupting log collection. A fixed version 1.8.5 is available. Until upgraded, strict IAM controls on S3 bucket write access can mitigate the risk.
CVSS v3.1
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The fluent-plugin-s3 plugin's in_s3 input reads and decompresses files from S3, including gzip, lzma2, and lzop formats. It does not limit the size of the decompressed data, allowing an attacker with sufficient permissions to upload a highly compressed file that decompresses to a very large size. This causes excessive memory consumption, potentially leading to an out-of-memory kill of the Fluentd process and resulting in denial of service. The vulnerability is tracked as CVE-2026-44162 and fixed in version 1.8.5.
Potential Impact
An attacker with write access to the monitored S3 bucket can cause Fluentd to consume excessive memory during decompression, leading to process termination by the OS and disruption of log collection on the affected node. There is no impact on confidentiality or integrity, only availability (denial of service).
Mitigation Recommendations
Upgrade fluent-plugin-s3 to version 1.8.5 or later, where this issue is fixed. If immediate upgrade is not possible, restrict write (PUT) permissions to the S3 bucket to trusted entities only, preventing untrusted or public uploads that could trigger the vulnerability.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-xv9w-7v6q-hpjh
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-44162"]
- Ecosystems
- ["RubyGems"]
- Database Specific Severity
- LOW
- Cvss Version
- 3.1
Threat ID: 6a3ef79427e9c79719ff8d69
Added to database: 06/26/2026, 22:05:08 UTC
Last enriched: 06/26/2026, 22:19:00 UTC
Last updated: 06/26/2026, 22:19:00 UTC
Views: 2
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