{"id":"CVE-2026-4035","aliases":["BIT-mlflow-2026-4035","GHSA-g35p-px32-whv6","PYSEC-2026-2222"],"url":"https://o3.security/vulnerability/CVE-2026-4035","summary":"Environment Variable Resolution Vulnerability in mlflow/mlflow","details":"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.","published":"2026-06-03T07:18:08.512Z","modified":"2026-07-23T03:56:16.768461341Z","cvss":{"score":7.7,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N"},"epss":{"score":0.00435,"percentile":0.3586,"asOf":"2026-08-09"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"mlflow","fixedVersion":"3.11.0"}],"fix":{"url":"https://github.com/mlflow/mlflow/commit/4a3f2f720cb4f058c9e0c5b883e0acc9ab64a7f3","label":"mlflow/mlflow@4a3f2f7"},"references":[{"type":"WEB","url":"https://huntr.com/bounties/f8e591a0-0f19-4910-b82e-16c9956f2233"},{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4035.json"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-4035"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/4xxx/CVE-2026-4035.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-4035"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2484318"},{"type":"FIX","url":"https://github.com/mlflow/mlflow/commit/4a3f2f720cb4f058c9e0c5b883e0acc9ab64a7f3"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-23T03:56:16.768461341Z"}}