CVE-2026-75033: Rancher: Cross-Cluster Secret Leakage via Namespace projectId Annotation Spoofing

Severity: high (CVSS 7.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-03 · updated 2026-09-18
Weakness: CWE-639

Description

A flaw was found in Rancher Manager. Project Secrets were propagated into a namespace based only on its `field.cattle.io/projectId` annotation, without verifying that the referenced project belonged to the same downstream cluster. A user able to create namespaces on one cluster could set the annotation to a project ID from another cluster and have that project's secrets copied into a namespace under their control. This issue affects Rancher: before 2.15.1.

Affected products

SUSE Rancher: before 2.15.1 — fixed in 2.15.1

How to fix

Upgrade to a fixed version: SUSE Rancher 2.15.1. Check the vendor advisory for mitigations.

References

https://github.com/rancher/rancher/releases/tag/v2.15.1

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