CVE-2026-78587

Incorrect Authorization (CWE-863) in Fleet Server can lead to a denial of service of agent upload operations via Privilege Abuse (CAPEC-122). Fleet Server does not correctly verify session ownership during multi-part data upload operations, allowing any authenticated agent to interfere with the active upload sessions belonging to other enrolled agents.

CVSS v3 3.1 LOW

3.1^/10

CVSS v3 : LOW

Vector :

Exploitability : 1.6 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://discuss.elastic.co/t/fleet-server-8-19-16-9-3-5-9-4-2-security-update-esa-2026-164/390117	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:elastic:fleet_server::::::::
	cpe:2.3:a:elastic:fleet_server::::::::
	cpe:2.3:a:elastic:fleet_server::::::::

History

No history.

Information

Published : 2026-09-02 15:17

Updated : 2026-09-03 19:11

NVD link : CVE-2026-78587

Mitre link : CVE-2026-78587

CVE.ORG link : CVE-2026-78587

JSON object : View

Products Affected

elastic

fleet_server

CWE

CWE-863

Incorrect Authorization

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