Path Traversal in Mosaicml Composer
CVE-2026-109153
A vulnerability was detected in MosaicML Composer up to 0.32.1. This affects the function tarball.extractall of the file composer/utils/checkpoint.py of the component Checkpoint Extraction. The manipulation results in path traversal. The attack can be executed remotely. The vendor was contacted early about this disclosure.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Mosaicml Composer — versions 0.32.0, 0.32.1
Weakness classification (CWE)
References
- vuldb.com/vuln/416887 (technical-description, vdb-entry)
- vuldb.com/vuln/416887/cti (signature, permissions-required)
- vuldb.com/cve/CVE-2026-109153 (third-party-advisory)
- vuldb.com/submit/978647 (third-party-advisory)
- github.com/mosaicml/composer/issues/3942 (issue-tracking)
- github.com/mosaicml/composer/ (product)
Frequently asked questions
- What is CVE-2026-109153?
- CVE-2026-109153 is a medium-severity vulnerability in Mosaicml Composer, classified under Path Traversal. CVSS score: 6.3/10. Published 2026-10-13.
- How severe is CVE-2026-109153?
- Medium severity. CVSS v3 base score is 6.3 out of 10.