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KibanaApplication · Elastic

CVE-2026-42399

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 low-privileged user can cause Kibana to consume exponentially increasing amounts of memory by submitting a specially crafted Timelion visualization expression containing deeply chained function calls. The resulting data structure grows without bound, exhausting available memory and causing the Kibana service to crash and become unavailable to all users.

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 · moderate confidence

Kibana's Timelion visualization feature contains an uncontrolled resource consumption vulnerability (CWE-400) where an authenticated low-privilege user can submit a specially crafted expression with deeply chained function calls. This causes the expression parser to build an exponentially growing data structure that consumes all available memory, leading to service crash and denial of service for all users.

MitigationApply vendor-supplied patches for Kibana that address Timelion expression parsing. Consider implementing interim rate limiting or expression complexity restrictions for low-privileged users until the patch can be deployed.

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

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. Identify if Kibana is installed
    Check for Kibana installation by looking for the kibana service or process: systemctl status kibana (Linux), or check for Kibana processes running (ps aux | grep kibana). Also check common installation paths like /usr/share/kibana, /opt/kibana, or C:\Program Files\Elastic\Kibana.
    Affected if Kibana is installed and running in the environment.
  2. Check installed Kibana version
    Run the command: curl -s http://localhost:5601/api/status or look in kibana/package.json for the version number. Compare the version against affected ranges: 8.0.0 to 8.19.15 (inclusive), or 9.0.0 to 9.3.4 (inclusive).
    Affected if The installed version falls within 8.0.0 to 8.19.15 or 9.0.0 to 9.3.4.
  3. Verify Timelion plugin is enabled
    Check if the Timelion plugin is available by accessing the Timelion visualization interface at http://localhost:5601/app/timelion or by checking kibana.yml configuration file for timelion.enabled: true setting.
    Affected if Timelion plugin is enabled and accessible to users.
  4. Check for low-privilege user access
    Review Kibana role-based access control (RBAC) settings to determine if authenticated users with low privileges (non-admin roles) have access to the Timelion application. Check kibana.yml or Kibana security settings for role permissions.
    Affected if Low-privilege authenticated users can access and create Timelion visualizations.
  5. Inspect for memory exhaustion indicators
    Monitor Kibana process memory usage (top, htop, or task manager) and check Kibana logs (kibana.log) for out-of-memory errors, crash reports, or repeated restarts that may indicate exploitation of this vulnerability.
    Affected if Kibana is experiencing memory exhaustion, frequent crashes, or denial of service, especially during Timelion expression evaluation.

If Kibana is installed with a version between 8.0.0-8.19.15 or 9.0.0-9.3.4, and the Timelion feature is accessible to low-privilege authenticated users, the environment is potentially affected by this CVE.

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 or later
Fixed in 8.19.169.3.5
Interim mitigation

Apply vendor-supplied patches for Kibana that address Timelion expression parsing. Consider implementing interim rate limiting or expression complexity restrictions for low-privileged users until the patch can be deployed.

Recommended fix High confidence

Kibana 8.19.16 (for 8.x branch) or 9.3.5 (for 9.x branch)

  1. 1. Back up your current Kibana configuration and any custom visualizations or dashboards.
  2. 2. Ensure you have adequate system resources and a maintenance window for the upgrade.
  3. 3. Download Kibana version 8.19.16 (if on 8.x branch) or 9.3.5 (if on 9.x branch) from the Elastic downloads page.
  4. 4. Stop the Kibana service on all nodes in your cluster.
  5. 5. Upgrade Kibana using your package manager (e.g., apt, yum) or by extracting the new tarball.
  6. 6. Verify the kibana.yml configuration file is compatible with the new version.
  7. 7. Start the Kibana service and monitor for successful startup.
  8. 8. Test that Timelion visualizations work correctly with the fix applied.
Caveat Review Elastic Kibana 8.19 and 9.3 release notes for any breaking changes or deprecations before upgrading

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

Fix this in Kibana Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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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-2026-42399 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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