Environment Variable Resolution Vulnerability in mlflow/mlflow

{
  "id": "d61b50aa7418cb841ec40d0df711116d2b91569e46ffe0425afdccdef571e9cc",
  "url": "https://osv.dev/vulnerability/CVE-2026-4035",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Environment Variable Resolution Vulnerability in mlflow/mlflow",
    "summary": "A vulnerability in mlflow/mlflow versions prior to 3.11.0 allows for the resolution of environment variables in AI Gateway secrets, which can be exploited to exfiltrate sensitive server-side environment credentials to an attacker-controlled endpoint. This issue arises because the `api_key` field in gateway secrets can accept `$ENV_VAR` references, which are resolved against the MLflow server's environment during runtime. The resolved secrets are then sent in provider authentication headers to the configured upstream `api_base`. This vulnerability can be exploited by low-privileged authenticated users in basic-auth deployments or by unauthenticated users in default deployments without `basic-auth`. The impact includes potential leakage of sensitive credentials such as cloud artifact credentials (`AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY`), which could lead to artifact poisoning and cross-boundary code execution in downstream environments. The issue is fixed in version 3.11.0.",
    "evidence": "osv:CVE-2026-4035",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-4035",
      "aliases": [
        "BIT-mlflow-2026-4035",
        "CVE-2026-4035",
        "GHSA-g35p-px32-whv6",
        "PYSEC-2026-2222"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/mlflow/mlflow",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "4a3f2f720cb4f058c9e0c5b883e0acc9ab64a7f3"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "fixed": "4a3f2f720cb4f058c9e0c5b883e0acc9ab64a7f3"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "nightly",
            "v3.0.0",
            "v2.2.0",
            "v1.7.0",
            "1.0.0",
            "v0.8.1",
            "v0.8.0",
            "v0.7",
            "v0.6.0",
            "v0.5.0",
            "v0.4.2",
            "v0.4.1",
            "v0.4.0",
            "v0.3.0",
            "v0.2.1",
            "v0.2.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-4035.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:39.884365201Z",
      "provider": "osv",
      "references": [
        "https://huntr.com/bounties/f8e591a0-0f19-4910-b82e-16c9956f2233",
        "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4035.json",
        "https://access.redhat.com/security/cve/CVE-2026-4035",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/4xxx/CVE-2026-4035.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-4035",
        "https://bugzilla.redhat.com/show_bug.cgi?id=2484318",
        "https://github.com/mlflow/mlflow/commit/4a3f2f720cb4f058c9e0c5b883e0acc9ab64a7f3"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-201"
        ],
        "cna_assigner": "@huntr_ai",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "fixed": "3.11.0"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "SplitRange"
              }
            ]
          },
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "fixed": "3.11.0"
                  },
                  {
                    "fixed": "3.11.0"
                  }
                ],
                "source": "DESCRIPTION"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/4xxx/CVE-2026-4035.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-4035",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 507517,
  "published_at": "2026-06-03T07:18:08.512+00:00"
}