Vulnerability in elk (CVE-2026-42400)
Summary
Vulnerability in elk (CVE-2026-42400). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 8.19.16, 9.3.5, 9.4.2 or later.
Original description
The description as published by the source.
Uncontrolled Resource Consumption (CWE-400) in Kibana can lead to denial of service via Excessive Allocation (CAPEC-130). An authenticated user can send a specially crafted compressed request payload that is processed prior to authorization checks, causing excessive memory and CPU resource consumption that can result in a Kibana instance becoming unresponsive or crashing.
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-2026-42400 has been found in elk.
Risk of unauthorized operations or information disclosure. CVSS score: 6.5/10.
What to do: upgrade elk to 8.19.16, 9.3.5, 9.4.2 or later.
If unsure, ask your IT team or search "elk CVE-2026-42400" on the vendor's site.
CVE-2026-42400 (elk) — CWE-400 / CVSS v3 6.5
Attack vector: remote (network-reachable) / no user interaction
Patched: 8.19.16, 9.3.5, 9.4.2 — 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-400) exists in elk.
Check the vendor advisory for the affected versions of elk.
Severity: Medium (CVSS 6.5/10). Risk of unauthorized operations or information disclosure.
Update to 8.19.16, 9.3.5, 9.4.2.
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 'elk' . 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 'elk' . | 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
elk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 elk to 8.19.16, 9.3.5, 9.4.2ステージング環境で 8.19.16, 9.3.5, 9.4.2 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 discuss.elastic.co
- web nvd.nist.gov
- web github.com