TI-2026-32144 Aliases CVE-2026-44162 GHSA-xv9w-7v6q-hpjh

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

LOW 14CWE-409Published 2026-09-14 · Updated 2026-09-14

Key facts

Attack vector: Network
Privileges required: High
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · Low
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-770.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00483 41st percentileScored 2026-11-07

Fix Fixed fluent-plugin-s3 (fluent): 1.8.5fluent-plugin-s3 (RubyGems): 1.8.5

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
fluent	fluent-plugin-s3	0.7.0 to before 1.8.5	1.8.5	Patch available	CNA
—	fluent-plugin-s3 (RubyGems)	0.7.0 to before 1.8.5	1.8.5	Patch available	GHSA-xv9w-7v6q-hpjh

fluent-plugin-s3 Vendorfluent Affected 0.7.0 to before 1.8.5 Fixed in 1.8.5 Patch available CNA
fluent-plugin-s3 (RubyGems) Vendor— Affected 0.7.0 to before 1.8.5 Fixed in 1.8.5 Patch available GHSA-xv9w-7v6q-hpjh

Remediation

Fix · CNA fluent-plugin-s3 (fluent) Fixed in 1.8.5
Fix · GHSA-xv9w-7v6q-hpjh fluent-plugin-s3 (RubyGems) Fixed in 1.8.5 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-44162
2026-10-03 Alias added: GHSA-xv9w-7v6q-hpjh

References

Other 4

TI-2026-44158 Fluent Bit: Remote stack buffer overflow in Fluent Bit `out_forward` Secure-Forward `PONG` handler CVSS 4.0CRITICAL 9.2
TI-2022-18753 Fluentd vulnerable to remote code execution due to insecure deserialization (in non-default configuration) CVSS 3.1CRITICAL 9.8
TI-2026-32064 Fluentd: Remote Code Execution (RCE) via Arbitrary File Write in `${tag}` Placeholder CVSS 3.1CRITICAL 9.8
TI-2017-07995 Escape sequence injection vulnerability in Fluentd versions 0.12.29 through 0.12.40 may… CVSS 3.0CRITICAL 9.8
TI-2020-14076 An issue was discovered in Fluent-ui v.1.2.2 allows attackers to gain escalated… CVSS 3.1HIGH 8.8
TI-2026-32142 Fluentd: Denial of Service (DoS) via Gzip Decompression Bomb in `in_http` and `in_forward` CVSS 3.1HIGH 7.5

See all 9 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences