CVE-2026-88808 HIGH

CVE-2026-88808: Fleet agent copies downstream resources with cluster-admin privileges, allowing cross-namespace writes on downstream clusters

Vendor Suse
Product Rancher
Weakness CWE-250
Published September 28, 2026
Last update September 28, 2026

CVSS base score

8.8/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

What the vulnerability does

01Description

A vulnerability has been identified within Rancher Manager where the Fleet agent wrote resources to downstream clusters using its own cluster-admin credentials instead of the ServiceAccount pinned to the deployment. It affects multi-tenancy environments where different tenants share the same downstream clusters, for example different privileged or untrusted teams inside the same organization. This could lead to overwritten configuration files. This issue affected SUSE Rancher Fleet 0.16 before 0.16.2, 0.15 before 0.15.7, and 0.14 before 0.14.11.

Key dates

02Disclosure timeline

September 28, 2026 CVE published
September 28, 2026 Record updated