CVE-2026-53995

NVD 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.

What to do

• No fixed release is known yet: follow the vendor advisory below and keep MLflow off the public internet until a fix ships.
• Do not expose the component's API or UI to the internet without authentication in front of it.

Sources

• NVD: CVE-2026-53995
• https://github.com/SaiTeja-Erukude/CVE-2026-53995-mlflow-path-traversal
• https://github.com/mlflow/mlflow/pull/26842
• https://www.vulncheck.com/advisories/mlflow-path-traversal-via-trace-id-api

Read more

• MLflow authorization CVEs 2026