How severe is CVE-2026-39961?

CVE-2026-39961 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-39961 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-39961?

CVE-2026-39961 affects Aiven Aiven Operator. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-39961?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-39961 have an EU (EUVD) identifier?

Yes. CVE-2026-39961 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-20965.

When was CVE-2026-39961 published?

CVE-2026-39961 was published on 2026-04-09 and last updated on 2026-06-17.

CVE-2026-39961

CVE-2026-39961 is a medium-severity vulnerability in Aiven Aiven Operator with a CVSS 3.x base score of 6.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-269.

Key facts

Severity: Medium (CVSS 3.x base score 6.8)
EPSS exploit prediction: 0% (31st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-20965
Weakness: CWE-269
Affected product: Aiven Aiven Operator
Published: 2026-04-09
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2026-39961?: 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 severe is CVE-2026-39961?: CVE-2026-39961 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-39961 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-39961?: CVE-2026-39961 affects Aiven Aiven Operator. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-39961?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-39961 have an EU (EUVD) identifier?: Yes. CVE-2026-39961 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-20965.
When was CVE-2026-39961 published?: CVE-2026-39961 was published on 2026-04-09 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:aiven:aiven_operator:*:*:*:*:*:*:*:*

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