CVE-2026-78587: Incorrect Authorization in Fleet Server Leading to Denial of Service of Agent Upload Operations

Published Sep 2, 2026
·
Updated

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.

Affected Software

1 affected component
Elastic Fleet Server

Event History

Sep 2, 2026
CVE Published
via MITRE·02:43 PM
Data Sourced
via MITRE·02:43 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·03:17 PM
DescriptionSeverityWeakness

Frequently Asked Questions

1

Who can exploit this issue?

An attacker needs to be an authenticated, enrolled Fleet agent. The issue allows one enrolled agent to interfere with active multi-part upload sessions belonging to other enrolled agents.

2

What is the operational impact?

The documented impact is denial of service affecting agent upload operations. The provided severity vector indicates no confidentiality or integrity impact, with availability impact limited to low.

3

Are unauthenticated or purely remote attackers affected by this requirement?

No. Although the attack vector is network-based, exploitation requires low-level privileges in the form of authenticated agent access; no user interaction is required.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203