High severity · published Sep 28, 2026
CVE-2026-88808
Fleet agent copies downstream resources with cluster-admin privileges, allowing cross-namespace writes on downstream clusters
8.8
CVSS
0.3%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 20% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RA
Rancher · SUSE
0.16.0 before 0.16.2; 0.15.0 before 0.15.7; 0.14.0 before 0.14.11 · source: vendor
RF
Rancher Fleet · Suse
0.14.0 before 0.14.11; 0.15.0 before 0.15.7; 0.16.0 before 0.16.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-88808
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-88808
vendor-advisory
https://github.com/rancher/fleet/security/advisories/GHSA-q9v4-358v-r8q5
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