Aiven Operator has cross-namespace secret exfiltration via ClickhouseUser connInfoSecretSource

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.8 · CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N

EPSS

• CVE-2026-39961: 0.40% estimated exploitation activity in the next 30 days; percentile 33.74 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact 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. Patches This vulnerability is resolved in version 0.37.0. We recommend all users update as soon as possible. Credits Credits to Andrés Cruciani for finding and reporting the bug through our bug bounty program

Published by the source

10 Apr 2026, 17:22 UTC

Last modified by the source

10 Apr 2026, 17:22 UTC

Source last checked

26 Oct 2026, 15:19 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-99j8-wv67-4c72

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# Patch Next advisory brief: CVE-2026-39961

Advisory: Aiven Operator has cross-namespace secret exfiltration via ClickhouseUser connInfoSecretSource
IDs: CVE-2026-39961, GHSA-99j8-wv67-4c72
Record: https://patchnext.com/advisories/cve-2026-39961 (revision 1, source checked 26 Oct 2026, 15:19 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/aiven/aiven-operator 0.37.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/aiven/aiven-operator: affected >= 0.31.0, < 0.37.0; fixed in 0.37.0

## Suggested inspection (read-only)
- Go github.com/aiven/aiven-operator: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/aiven/aiven-operator.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-99j8-wv67-4c72 (GitHub-reviewed advisory GHSA-99j8-wv67-4c72 lists affected ranges: Go github.com/aiven/aiven-operator >=0.31.0 <0.37.0)

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