dbcve.org
KibanaApplication · Elastic

CVE-2026-42400

MEDIUM · 6.5 CVSS v3.1 Published 2026-05-28
Fix available
A fix is available. Upgrade to 8.19.16 / 9.3.5 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Kibana suffers from uncontrolled resource consumption where an authenticated user can send specially crafted compressed request payloads that are processed before authorization checks, causing excessive memory and CPU consumption leading to denial of service.

MitigationApply vendor patches that implement resource limits on compressed request payload decompression and/or move authorization checks earlier in the request processing pipeline to prevent resource exhaustion.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
KibanaApplication
Affected:>= 8.0.0, < 8.19.16>= 9.0.0, < 9.3.5>= 9.4.0, < 9.4.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Determine installed Kibana version
    Run `kibana --version` or check the version field in the Kibana welcome page, or look at the package.json file in the Kibana installation directory
    Affected if The version falls within one of these ranges: >= 8.0.0 and < 8.19.16; >= 9.0.0 and < 9.3.5; >= 9.4.0 and < 9.4.2
  2. Verify compressed request payload handling is enabled
    Check Kibana configuration file (kibana.yml) for settings related to request body parsing, compression, or payload handling. Look for `server.maxPayload` or similar compression-related settings that may be present and not explicitly disabled
    Affected if Compressed request handling is enabled (this is typically the default configuration)
  3. Confirm authentication is active
    Verify that Kibana has authentication configured and enabled. Check that `xpack.security.authc` settings in kibana.yml show authentication providers are configured and active
    Affected if Authentication is enabled (which is required for the authenticated user to exploit this vulnerability)
  4. Check for evidence of resource exhaustion
    Monitor Kibana process memory and CPU usage. Look for unusually high resource consumption that correlates with compressed request handling, or review access logs for patterns of compressed requests
    Affected if Unusually high memory or CPU usage is observed when processing compressed requests, especially from authenticated users

You are affected if your Kibana version is within any of the affected version ranges AND compressed request handling is enabled AND users are authenticated, as the vulnerability allows authenticated users to exhaust resources via specially crafted compressed payloads processed before authorization.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 8.19.16 / 9.3.5 / 9.4.2 or later
Fixed in 8.19.169.3.59.4.2
Interim mitigation

Apply vendor patches that implement resource limits on compressed request payload decompression and/or move authorization checks earlier in the request processing pipeline to prevent resource exhaustion.

Recommended fix High confidence

Kibana 8.19.16+ (for 8.x line), 9.3.5+ (for 9.0-9.3 line), or 9.4.2+ (for 9.4 line)

  1. 1. Identify the current Kibana version in use using `kibana --version` or the KibanaAbout page
  2. 2. For Kibana 8.x versions: Plan upgrade to version 8.19.16 or later
  3. 3. For Kibana 9.0.x - 9.3.x versions: Plan upgrade to version 9.3.5 or later
  4. 4. For Kibana 9.4.0 - 9.4.1 versions: Plan upgrade to version 9.4.2 or later
  5. 5. Before upgrading in production, test the new version in a staging environment
  6. 6. Back up Kibana configuration files (kibana.yml) and any custom dashboards/visualizations
  7. 7. Perform the upgrade following Elastic's standard upgrade documentation
  8. 8. After upgrade, verify Kibana starts successfully and is responsive
Caveat Standard minor version upgrade; review Elastic Stack upgrade notes for any deprecation warnings specific to your version

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Kibana Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,680
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-42400 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data