CVE-2026-39961
MEDIUMDescription
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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N
Exploit Intelligence
Low risk: more likely to be exploited than 32% of all known CVEs.
References
Related Vulnerabilities
Other CWE-269 (Improper Privilege Management) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2017-12635 | Critical | 9.8 | 100% | - | Fix |
| CVE-2022-24637 | Critical | 9.8 | 99% | - | Fix |
| CVE-2017-5689 | Critical | 9.8 | 92% | KEV | Fix |
| CVE-2020-3243 | Critical | 9.8 | 88% | - | - |
| CVE-2024-21888 | High | 8.8 | 87% | - | - |
| CVE-2022-0441 | Critical | 9.8 | 85% | - | Fix |
Common questions
How do I fix CVE-2026-39961?
Upgrade aiven operator to 0.37.0 or later.
Is CVE-2026-39961 being actively exploited?
Not that we know of. CVE-2026-39961 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.40% is the estimated probability that it will be exploited in the next 30 days. That is higher than 32% of all scored CVEs.
How severe is CVE-2026-39961?
CVE-2026-39961 has a CVSS v3 base score of 6.8, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-39961 affect?
Published advisories record a fix for aiven operator (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2026-39961
Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-13.