CVE-2026-53995

01/Description

MLflow 3.17.1 and earlier contains a path traversal vulnerability in the FileStore tracking backend that allows unauthenticated attackers to control filesystem paths by submitting a crafted trace ID containing traversal sequences to the POST /api/3.0/mlflow/traces endpoint. Attackers can exploit FileStore.start_trace() to write trace_info.yaml, request_metadata, and tag files with attacker-controlled metadata outside the intended experiment trace directory, subject to the server process's filesystem permissions. FileStore is the default tracking backend before MLflow 3.7.0 and opt-in thereafter (the default changed to a SQLite database), so deployments in the earlier part of the affected range are vulnerable without special configuration while later ones are affected only when FileStore is explicitly selected.

02/References4

• github.com/SaiTeja-Erukude/CVE-2026-53995-mlflow-path-traversal
• github.com/mlflow/mlflow/commit/d64cc8b673f71d29d93a7845fc17994…
• github.com/mlflow/mlflow/pull/26842
• www.vulncheck.com/advisories/mlflow-path-traversal-via-trace-id…