Vulnerability in fluentd (CVE-2026-44025)
Summary
Vulnerability in fluentd (CVE-2026-44025). Confidential information can be exposed externally. Exploitable via in_monitor_agent. Mitigation: upgrade to 1.19.3 or later.
Original description
The description as published by the source.
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.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-44025 has been found in fluentd.
Attackers can target a specific entry point like in_monitor_agent over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.5/10.
What to do: upgrade fluentd to 1.19.3 or later.
If unsure, ask your IT team or search "fluentd CVE-2026-44025" on the vendor's site.
CVE-2026-44025 (fluentd) — CWE-306 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: in_monitor_agent / localhost
Patched: 1.19.3 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-306) exists in fluentd. Attackers reach the vulnerable code path via in_monitor_agent without authentication.
Check the vendor advisory for the affected versions of fluentd. Attack surface: in_monitor_agent / localhost.
Severity: High (CVSS 7.5/10). Confidential information can be exposed externally.
Update to 1.19.3.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'fluentd' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'fluentd' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
fluentdを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade fluentd to 1.19.3ステージング環境で 1.19.3 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- patch github.com
- patch github.com
- web github.com
- web github.com