Elasticsearch PKI Realm Authentication Bypass Vulnerability Allows User Impersonation Through Crafted Client Certificates

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2025-37731: 0.19% estimated exploitation activity in the next 30 days; percentile 8.89 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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.

Published by the source

15 Dec 2025, 12:30 UTC

Last modified by the source

25 Sep 2026, 17:36 UTC

Source last checked

26 Oct 2026, 16:55 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-m9gh-789g-q5pv

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# Patch Next advisory brief: CVE-2025-37731

Advisory: Elasticsearch PKI Realm Authentication Bypass Vulnerability Allows User Impersonation Through Crafted Client Certificates
IDs: CVE-2025-37731, GHSA-m9gh-789g-q5pv
Record: https://patchnext.com/advisories/cve-2025-37731 (revision 1, source checked 26 Oct 2026, 16:55 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.elasticsearch.plugin:x-pack-security 9.2.2, 9.1.8, 8.19.8; org.elasticsearch.plugin:x-pack-core 9.2.2, 9.1.8, 8.19.8. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.elasticsearch.plugin:x-pack-security: affected >= 7.0.0-alpha1, < 8.19.8; >= 9.0.0-beta1, < 9.1.8; >= 9.2.0, < 9.2.2; fixed in 9.1.8, 8.19.8, 9.2.2
- Maven org.elasticsearch.plugin:x-pack-core: affected >= 7.0.0-alpha1, < 8.19.8; >= 9.0.0-beta1, < 9.1.8; >= 9.2.0, < 9.2.2; fixed in 9.1.8, 8.19.8, 9.2.2

## Suggested inspection (read-only)
- Maven org.elasticsearch.plugin:x-pack-security: check the installed version with your package manager.
- Maven org.elasticsearch.plugin:x-pack-core: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.elasticsearch.plugin:x-pack-security, org.elasticsearch.plugin:x-pack-core.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-m9gh-789g-q5pv (GitHub-reviewed advisory GHSA-m9gh-789g-q5pv lists affected ranges: Maven org.elasticsearch.plugin:x-pack-security >=7.0.0-alpha1 =9.0.0-beta1 =9.2.0 =7.0.0-alpha1 =9.0.0-beta1 =9.2.0 <9.2.2)

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