Vulnerability · Published Oct 13, 2026 · Assigned by VulDB
CVE-2026-109153MosaicML Composer Checkpoint Extraction checkpoint.py tarball.extractall path traversal
Medium 6.3
In plain English
A medium-severity path traversal in Composer from MosaicML. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities).
Severity (CVSS 3.1)6.3Medium
Exploit odds (30 days)0.5%top 57.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
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.
Affected products (as reported)
Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L/E:X/RL:X/RC:C
References
- VDB-416887 | MosaicML Composer Checkpoint Extraction checkpoint.py tarball.extractall path traversal vdb-entry, technical-description
- VDB-416887 | CTI Indicators (IOB, IOC, TTP, IOA) signature, permissions-required
- CVE-2026-109153 | CVE Analysis and Report third-party-advisory
- Submit #978647 | mosaicml composer 0.32.1 Path Traversal third-party-advisory
- https://github.com/mosaicml/composer/issues/3942 issue-tracking
- https://github.com/mosaicml/composer/ product