Auth bypass in Fluent Fluentd
CVE-2026-44025
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 Monitor Agent plugin in_monitor_agent exposes internal metrics and plugin information via a REST API, and responses from /api/plugins.json and related endpoints unintentionally include internal instance variables that may contain database passwords, API keys, or cloud credentials. This issue is fixed in version 1.19.3.
Vulnerability class: Broken Authentication
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:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.005 (39.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 39.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- Fluent Fluentd — versions < 1.19.3
- Fluentd
Weakness classification (CWE)
References
- github.com/fluent/fluentd/security/advisories/GHSA-pr7j-96cj-549h (Patch, Vendor Advisory)
- github.com/fluent/fluentd/pull/5392 (Patch, Issue Tracking)
- github.com/fluent/fluentd/commit/990921518971699b9a97441970674d1800e29177 (Patch)
- github.com/fluent/fluentd/releases/tag/v1.19.3 (Release Notes)
Frequently asked questions
- What is CVE-2026-44025?
- CVE-2026-44025 is a high-severity vulnerability in Fluent Fluentd, classified under Missing Authentication for Critical Function. CVSS score: 7.5/10. Published 2026-07-08.
- How severe is CVE-2026-44025?
- High severity. CVSS v3 base score is 7.5 out of 10.