Incorrect Authorization in Fleet Server Leading to Denial of Service of Agent Upload Operations
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 Versions:
- 8.x: All versions from 8.0.0 up to and including 8.19.15
- 9.x:
- All versions from 9.0.0 up to and including 9.3.4
- All versions from 9.4.0 up to and including 9.4.1
Affected Configurations:
All configurations are affected.
Solutions and Mitigations:
The issue is resolved in Fleet Server versions 8.19.16, 9.3.5, and 9.4.2.
For Users that Cannot Upgrade:
There are no workarounds for this vulnerability.
Indicators of Compromise (IOC)
No specific indicators of compromise have been identified for this vulnerability.
Severity: CVSSv3.1: Low ( 3.1 ) - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
CVE ID: CVE-2026-78587
Problem Type: CWE-863 - Incorrect Authorization
Impact: CAPEC-122 - Privilege Abuse