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ElasticsearchDatabase / datastore · Elastic

CVE-2025-37731

HIGH · 7.4 CVSS v3.1 Published 2025-12-15
Fix available
A fix is available. Upgrade to 8.19.8 / 9.1.8 or later.
See remediation →
83/100
Remediation priority · High
Remotely reachable No privileges 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
Improper Authentication in Elasticsearch PKI realm can lead to user impersonation via specially crafted client certificates. A malicious actor would need to have such a crafted client certificate signed by a legitimate, trusted Certificate Authority.

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

Elasticsearch PKI realm contains an improper authentication flaw where specially crafted client certificates can be used to impersonate legitimate users. The vulnerability allows authentication bypass through malformed certificate attributes that the PKI realm incorrectly accepts as valid identity claims, despite having been signed by a trusted Certificate Authority.

MitigationApply Elasticsearch security updates or patches addressing certificate validation in the PKI realm. Review and tighten PKI realm certificate subject/attribute validation rules as an interim measure.

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
ElasticsearchDatabase / datastore
Affected:>= 7.0.0, <= 7.17.29>= 8.0.0, < 8.19.8>= 9.0.0, < 9.1.8>= 9.2.0, < 9.2.2

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
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

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

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. Verify PKI realm is enabled
    Check elasticsearch.yml for pki realm configuration under xpack.security.authc.realms.pki settings, or query the GET /_security/realm endpoint
    Affected if PKI realm is configured and active in Elasticsearch
  2. Check installed Elasticsearch version
    Run `curl -k https://localhost:9200` with credentials or check the installed package version via system package manager (dpkg -r, rpm -q)
    Affected if Version falls within >= 7.0.0 <= 7.17.29, >= 8.0.0 < 8.19.8, >= 9.0.0 < 9.1.8, or >= 9.2.0 < 9.2.2
  3. Inspect PKI realm certificate configuration
    Query GET /_security/realm/<realm_name> or review elasticsearch.yml for xpack.security.authc.realms.pki.* settings, specifically looking at files attribute and any DN templates configured
    Affected if PKI realm is using default certificate subject mapping without explicit attribute validation rules
  4. Check for client certificate authentication usage
    Review Elasticsearch audit logs (if enabled) for authentication events with certificate-based login, or check application logs for PKI authentication attempts
    Affected if Users or services are actively authenticating using client certificates via the PKI realm

User is affected if Elasticsearch PKI realm is enabled AND the installed version is within the affected ranges AND client certificate authentication is in use.

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 8.19.8 / 9.1.8 / 9.2.2 or later
Fixed in 8.19.89.1.89.2.2
Interim mitigation

Apply Elasticsearch security updates or patches addressing certificate validation in the PKI realm. Review and tighten PKI realm certificate subject/attribute validation rules as an interim measure.

Recommended fix Moderate confidence

Elasticsearch 7.17.30, 8.19.8, 9.1.8, or 9.2.2 (depending on your major version)

  1. 1. Backup your Elasticsearch cluster configuration and data
  2. 2. Plan a maintenance window - upgrade should be done during low-traffic period
  3. 3. For Elasticsearch 7.x users: upgrade to version 7.17.30
  4. 4. For Elasticsearch 8.x users: upgrade to version 8.19.8
  5. 5. For Elasticsearch 9.0.x users: upgrade to version 9.1.8
  6. 6. For Elasticsearch 9.2.x users: upgrade to version 9.2.2
  7. 7. After upgrade, verify PKI realm authentication is working correctly
  8. 8. Test that legitimate client certificates authenticate as expected
Caveat Review Elastic Stack Upgrade Guide for any migration changes between versions; minor version upgrades typically have minimal breaking changes

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

Fix this in Elasticsearch Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.

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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-2025-37731 in production — separate from our analysis above.

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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