Arbitrary file write via unchecked tar entries
Published Mar 18, 2026 · Updated Mar 18, 2026
Path traversal in MLflow before 3.9.0rc0 allows attackers to write files outside the pyfunc extraction directory via crafted archives. The extract_archive_to_dir function calls tarfile.extractall without rejecting absolute, parent-directory, or symlink-mediated member paths. Exploitation requires ingestion of an untrusted pyfunc tar archive; the direct consequence is an attacker-selected file overwrite, while code execution depends on a target that the host later loads.
Summary
What happened
Path traversal in MLflow before 3.9.0rc0 allows attackers to write files outside the pyfunc extraction directory via crafted archives. The extract_archive_to_dir function calls tarfile.extractall without rejecting absolute, parent-directory, or symlink-mediated member paths. Exploitation requires ingestion of an untrusted pyfunc tar archive; the direct consequence is an attacker-selected file overwrite, while code execution depends on a target that the host later loads.
The record
- CVE
- CVE-2025-15031
- Published
- Mar 18, 2026
- Updated
- Mar 18, 2026
- Vendor
- MLflow Project
- Product
- MLflow
- Classifications
- CWE-22
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 18, 2026CVE publishedPublication date reported by the CVE source.
- Mar 18, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=unspecified <=latest
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Huntr MLflow tar-traversal proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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