What’s Vulnerable › Vulnerabilities

CVE-2026-39961: Aiven Operator has cross-namespace secret exfiltration via ClickhouseUser connInfoSecretSource

• Severity: medium (CVSS 4.9 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-09 · updated 2026-10-26
• Weakness: CWE-269

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 products

• aiven-operator: from 0.31.0 before 0.37.0 — fixed in 0.37.0

How to fix

Upgrade to a fixed version: aiven-operator 0.37.0. Check the vendor advisory for mitigations.

References

• https://github.com/aiven/aiven-operator/commit/032c9ba63257fdd2fddfb7f73f71830e371ff182
• https://github.com/aiven/aiven-operator/releases/tag/v0.37.0
• https://github.com/aiven/aiven-operator/security/advisories/GHSA-99j8-wv67-4c72

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