What is CVE-2026-72657?

CVE-2026-72657 is a medium-severity vulnerability in Elastic Fleet Server, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 6.5/10. Published 2026-08-13.

How severe is CVE-2026-72657?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Auth bypass in Elastic Fleet Server

CVE-2026-72657

Authorization Bypass Through User-Controlled Key (CWE-639) in Fleet Server can lead to information disclosure via Manipulating User-Controlled Variables (CAPEC-77). The authorization decision for artifact downloads relied on a client-supplied value that was persisted without being validated against the server-side record of the requesting agent's assignment. An authenticated party in possession of a valid enrolled agent credential could therefore retrieve a policy the agent is not assigned to.

Vulnerability class: IDOR (Insecure Direct Object Reference)

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

Affected products

Elastic Fleet Server — versions 8.3.0, 9.0.0, 9.5.0

Weakness classification (CWE)

CWE-639 — Authorization Bypass Through User-Controlled Key

References

security@elastic.co

Frequently asked questions

What is CVE-2026-72657?: CVE-2026-72657 is a medium-severity vulnerability in Elastic Fleet Server, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 6.5/10. Published 2026-08-13.
How severe is CVE-2026-72657?: Medium severity. CVSS v3 base score is 6.5 out of 10.