Bug 2555862 (CVE-2026-53995)

Summary: CVE-2026-53995 mlflow: mlflow: Arbitrary file write via FileStore path traversal
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: ilpinto, ltomasbo, ykashtan
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in MLflow. An unauthenticated remote attacker can achieve arbitrary file write by submitting a crafted trace identifier containing path traversal sequences to the FileStore tracking backend. This vulnerability allows the attacker to write metadata files outside the intended directory on the server's filesystem, subject to the server process's file permissions.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-10-19 21:21:44 UTC 
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.