A vulnerability has been identified within Rancher where a user with the ability to create a project, on a certain cluster, can create a project with the same name as an existing project in a different cluster. This results in the user gaining access to the other project in the different cluster, resulting in a privilege escalation. This happens because the namespace used on the local cluster to store related resources (PRTBs and secrets) is the name of the project.
Please consult the associated MITRE ATT&CK - Technique - Privilege Escalation for further information about this category of attack.
Patched versions include releases v2.11.1, v2.10.5, v2.9.9.
The fix involves the following changes:
Rancher:
Rancher Webhook:
project.Status.BackingNamespace to be SafeConcatName(project.Spec.ClusterName, project.Name);projectName and Namespace had to be the same for PRTBs, since PRTBs now go in project.BackingNamespace;BackingNamespace isn't set, set it to project.Name. For existing objects after update this will help unify them to the new projects.BackingNamespace can't be edited after it's set.Note: Rancher v2.8 release line does not have the fix for this CVE. The fix for v2.8 was considered too complex and with the risk of introducing instabilities right before this version goes into end-of-life (EOL), as documented in SUSE’s Product Support Lifecycle page. Please see the section below for workarounds or consider upgrading to a newer and patched version of Rancher.
If you can't upgrade to a fixed version, please make sure that:
To identify if this security issue could have been abused within your system, you need to find if there are any projects with the same name but on different clusters. To do that, run the following command in the local cluster as an administrator:
kubectl get projects -A -o=custom-columns='NAME:metadata.name' | sort | uniq -c
That command will list all project names, and show the instances of each name. Any project with more than 1 instance is affected by this security issue. To remedy the situation, the projects will need to be deleted and re-created to ensure no namespace collisions happen. While it would be possible to delete all but 1 of the projects with the same name, this is unadvisable because a user could have given themselves access to the wrong project.
If you have any questions or comments about this advisory:
| Software | From | Fixed in |
|---|---|---|
github.com/rancher/rancher
|
2.8.0 | 2.9.9 |
github.com/rancher/rancher
|
2.10.0 | 2.10.5 |
github.com/rancher/rancher
|
2.11.0 | 2.11.1 |
A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.
Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.