Vulnerability in fluentd (CVE-2026-44160)
Summary
Vulnerability in fluentd (CVE-2026-44160). Risk of unauthorized operations or information disclosure. Exploitable via in_http. 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 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.
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-2026-44160 has been found in fluentd.
Attackers can target a specific entry point like in_http over the network to misuse the product.
Risk of unauthorized operations or information disclosure. 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-2026-44160" on the vendor's site.
CVE-2026-44160 (fluentd) — CWE-409 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: in_http / in_forward / body_size_limit / chunk_size_limit
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-409) exists in fluentd. Attackers reach the vulnerable code path via in_http without authentication.
Check the vendor advisory for the affected versions of fluentd. Attack surface: in_http / in_forward / body_size_limit / chunk_size_limit.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
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