Auth bypass in Elastic Elasticsearch

CVE-2025-37731

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.

Vulnerability class: Broken Authentication

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.002 (7.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 8th percentile — 7.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-37731: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: -0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-37731?
CVE-2025-37731 is a medium-severity vulnerability in Elastic Elasticsearch, classified under Improper Authentication. CVSS score: 6.8/10. Published 2025-12-15.
How severe is CVE-2025-37731?
Medium severity. CVSS v3 base score is 6.8 out of 10.