ElasticCVE-2026-78587
Elastic Fleet Server: improper authorization
Low3.1CVE-2026-78587 · Published Sep 2, 2026 · updated Sep 3, 2026
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
| Package | Affected | Fixed in |
|---|---|---|
| Fleet Server Product | >= 8.0.0, <= 8.19.15 | No fix yet |
| >= 9.0.0, <= 9.3.4 | No fix yet | |
| >= 9.4.0, <= 9.4.1 | No fix yet |
Details and references
- CVSS 3.1
- CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
- Severity from
- the vendor (its own CVE record or advisory)
- Weakness
- CWE-863
More Elastic advisories
All Elastic| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Sep 2 | Elastic Kibana: improper authorization | Medium4.3 | No fix yet |
| Sep 2 | Elastic Kibana: path traversal | Medium6.5 | No fix yet |
| Sep 2 | Elastic Eck Operator: incomplete cleanup | Low3.5 | No fix yet |
| Sep 2 | Elastic Kibana: missing authorization | Medium5.5 | No fix yet |
| Sep 2 | Elastic Maps Server: path traversal | Medium5.3 | No fix yet |
| Sep 2 | Elastic Agent: insecure permissions | High7.8 | No fix yet |