BIT-fluentd-2026-44160: Fluentd: Denial of Service (DoS) via Gzip Decompression Bomb in `in_http` and `in_forward`
Fluentd collects events from various data sources and writes them to files, RDBMS, NoSQL, IaaS, SaaS, Hadoop and so on. Prior to 1.19.3, Fluentd's in_http and in_forward plugins support gzip-compressed data but enforce limits only on compressed payloads through settings such as body_size_limit and chunk_size_limit, allowing crafted compressed payloads to decompress in memory to an excessive size and cause denial of service through memory exhaustion. This issue is fixed in version 1.19.3.
AI Analysis
Technical Summary
Fluentd before version 1.19.3 has a denial of service vulnerability (CVE-2026-44160) in its in_http and in_forward plugins due to unrestricted gzip decompression size. An attacker can exploit this by sending a malicious gzip-compressed payload that decompresses to a very large size, exhausting memory resources and causing the Fluentd process to be killed. This disrupts the logging infrastructure relying on Fluentd. The vulnerability is classified under CWE-409 (Improper Resource Shutdown or Release) and has a CVSS 3.1 vector indicating network attack vector, low attack complexity, no privileges or user interaction required, and high impact on availability.
Potential Impact
Successful exploitation results in denial of service by exhausting memory during gzip decompression, causing the Fluentd process to be terminated by the operating system. This disrupts log collection and forwarding, potentially impacting monitoring and incident response capabilities.
Mitigation Recommendations
A fix is available in Fluentd version 1.19.3. Users should upgrade to version 1.19.3 or later to remediate this vulnerability. No other mitigations are indicated by the vendor advisory.
BIT-fluentd-2026-44160: Fluentd: Denial of Service (DoS) via Gzip Decompression Bomb in `in_http` and `in_forward`
Description
Fluentd collects events from various data sources and writes them to files, RDBMS, NoSQL, IaaS, SaaS, Hadoop and so on. Prior to 1.19.3, Fluentd's in_http and in_forward plugins support gzip-compressed data but enforce limits only on compressed payloads through settings such as body_size_limit and chunk_size_limit, allowing crafted compressed payloads to decompress in memory to an excessive size and cause denial of service through memory exhaustion. This issue is fixed in version 1.19.3.
CVSS v3.1
Score 7.5high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Fluentd before version 1.19.3 has a denial of service vulnerability (CVE-2026-44160) in its in_http and in_forward plugins due to unrestricted gzip decompression size. An attacker can exploit this by sending a malicious gzip-compressed payload that decompresses to a very large size, exhausting memory resources and causing the Fluentd process to be killed. This disrupts the logging infrastructure relying on Fluentd. The vulnerability is classified under CWE-409 (Improper Resource Shutdown or Release) and has a CVSS 3.1 vector indicating network attack vector, low attack complexity, no privileges or user interaction required, and high impact on availability.
Potential Impact
Successful exploitation results in denial of service by exhausting memory during gzip decompression, causing the Fluentd process to be terminated by the operating system. This disrupts log collection and forwarding, potentially impacting monitoring and incident response capabilities.
Mitigation Recommendations
A fix is available in Fluentd version 1.19.3. Users should upgrade to version 1.19.3 or later to remediate this vulnerability. No other mitigations are indicated by the vendor advisory.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-j9cw-hwqf-85w7
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-44160"]
- Ecosystems
- ["RubyGems"]
- Database Specific Severity
- HIGH
- Cvss Version
- 3.1
Threat ID: 6a3ef79627e9c79719ff8e7c
Added to database: 06/26/2026, 22:05:10 UTC
Last enriched: 07/09/2026, 08:11:03 UTC
Last updated: 08/10/2026, 05:02:07 UTC
Views: 93
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