CVE-2026-78587
Low
Description
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.
SeverityLow
CVSS3.1
Exploit probability—
ProductElastic Fleet Server
PublishedSep 2, 2026
First seenSep 2, 2026
Weakness typeCWE-863Incorrect authorization
How to fix
Update
- elastic fleet_server8.19.16, 9.3.5, 9.4.2 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| elastic fleet_server | 8.0.0 ≤ v < 8.19.16, 9.0.0 ≤ v < 9.3.5, 9.4.0 ≤ v < 9.4.2 | 8.19.16, 9.3.5, 9.4.2 |
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