Vulnerability in Fluent Fluentd
CVE-2026-44160
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.006 (48.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 48th percentile — 48.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Fluent Fluentd — versions < 1.19.3
- Fluentd
Weakness classification (CWE)
References
- github.com/fluent/fluentd/security/advisories/GHSA-j9cw-hwqf-85w7 (Mitigation, Vendor Advisory)
- github.com/fluent/fluentd/pull/5393 (Patch, Issue Tracking)
- github.com/fluent/fluentd/commit/f5f2b7cddf8aab3932e6dec9fa367a5f3eb27e10 (Patch)
- github.com/fluent/fluentd/releases/tag/v1.19.3 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-44160?
- CVE-2026-44160 is a high-severity vulnerability in Fluent Fluentd, classified under Improper Handling of Highly Compressed Data (Data Amplification). CVSS score: 7.5/10. Published 2026-07-08.
- How severe is CVE-2026-44160?
- High severity. CVSS v3 base score is 7.5 out of 10.