CVE-2026-53995

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.

CVSS 4.0

8.8CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N

CVSS 3.1

8.2CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L

EPSS

0.6% chance of exploitation in the next 30 days; higher than 48% of CVEs (scores of 2026-10-25)

CWE

CWE-22

Published

2026-10-19

Modified

2026-10-20

Record from

the NVD, synced 2026-10-21

Packages (OSV)

References

• 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

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