Vulnerability · Published Apr 9, 2026 · Assigned by GitHub_M
CVE-2026-39961Aiven Operator has cross-namespace secret exfiltration via ClickhouseUser connInfoSecretSource
Medium 6.8
In plain English
A medium-severity privilege mismanagement in aiven-operator from aiven. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Aiven Operator allows you to provision and manage Aiven Services from your Kubernetes cluster. From 0.31.0 to before 0.37.0, a developer with create permission on ClickhouseUser CRDs in their own namespace can exfiltrate secrets from any other namespace — production database credentials, API keys, service tokens — with a single kubectl apply. The operator reads the victim's secret using its ClusterRole and writes the password into a new secret in the attacker's namespace. The operator acts as a confused deputy: its ServiceAccount has cluster-wide secret read/write (aiven-operator-role ClusterRole), and it trusts user-supplied namespace values in spec.connInfoSecretSource.namespace without validation. No admission webhook enforces this boundary — the ServiceUser webhook returns nil, and no ClickhouseUser webhook exists. This vulnerability is fixed in 0.37.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/aiven/aiven-operator | 0.37.0 | GHSA-99j8-wv67-4c72 |
| Go | github.com/aiven/aiven-operator | 0.37.0 | GO-2026-5283 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| aiven | aiven-operator | < 0.37.0 |
Weakness: CWE-269, CWE-441 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N