CVE-2026-72657 Authorization Bypass Through User-Controlled Key in Fleet Server Leading to Information Disclosure

Medium 6.5 Published 13 Aug 2026 Updated 13 Aug 2026

An authenticated attacker with valid agent credentials can retrieve unauthorized policy artifacts due to missing server-side validation of client-supplied keys.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-72657?

CVE-2026-72657 is a medium-severity missing authorization vulnerability in Elastic Fleet Server, published on 13 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

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.

Weakness: CWE-639

Which versions are affected by CVE-2026-72657?

It affects 1 product.

Products include Elastic Fleet Server.

How do I fix CVE-2026-72657?

No fix has been published for CVE-2026-72657 yet. Limit exposure of the affected software until one is available.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-72657 being exploited?

There is no known exploitation of CVE-2026-72657 in the wild and no public exploit code.

Sources

Also known as GHSA-4ppv-hgww-58v5.