Aiven Operator has cross-namespace secret exfiltration via ClickhouseUser connInfoSecretSource

{
  "id": "0f23918a5fe0a57dab04124d3ef44447401ecc9785c4335fba1ec9ea7f77f71f",
  "url": "https://osv.dev/vulnerability/CVE-2026-39961",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Aiven Operator has cross-namespace secret exfiltration via ClickhouseUser connInfoSecretSource",
    "summary": "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.",
    "evidence": "osv:CVE-2026-39961",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-39961",
      "aliases": [
        "CVE-2026-39961",
        "GHSA-99j8-wv67-4c72",
        "GO-2026-5283"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/aiven/aiven-operator",
              "type": "GIT",
              "events": [
                {
                  "introduced": "ee09b203177652dff932e6ef2c8fed4aaaec736d"
                },
                {
                  "fixed": "43b74ef7c5b2cc719fa8057c771db0aa7d2fac9e"
                },
                {
                  "fixed": "032c9ba63257fdd2fddfb7f73f71830e371ff182"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:aiven:aiven_operator:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0.31.0"
                      },
                      {
                        "fixed": "0.37.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "032c9ba63257fdd2fddfb7f73f71830e371ff182"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "43b74ef7c5b2cc719fa8057c771db0aa7d2fac9e"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v0.37.0"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.36.0",
            "v0.35.0",
            "v0.34.0",
            "v0.33.1",
            "v0.31.0",
            "v0.33.0",
            "v0.32.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-39961.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:44.072044195Z",
      "provider": "osv",
      "references": [
        "https://github.com/aiven/aiven-operator/releases/tag/v0.37.0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39961.json",
        "https://github.com/aiven/aiven-operator/security/advisories/GHSA-99j8-wv67-4c72",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-39961",
        "https://github.com/aiven/aiven-operator/commit/032c9ba63257fdd2fddfb7f73f71830e371ff182"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-269",
          "CWE-441"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39961.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-39961",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 511712,
  "published_at": "2026-04-09T17:14:07.33+00:00"
}