CVE-2026-109156: Path Traversal in SeldonIO MLServer

This vulnerability in SeldonIO MLServer up to version 1.6.1 involves a path traversal issue in the _extract_env function of the mlserver/env.py file, specifically within the environment_tarball handler component. An attacker can remotely exploit this flaw by manipulating file paths, which may lead to unauthorized file access or directory traversal. The vendor was contacted but did not provide a response or patch. No known exploits are reported in the wild.

The vulnerability allows remote attackers to perform path traversal via the environment_tarball handler, potentially enabling unauthorized access to files outside the intended directory. This could lead to information disclosure or other impacts depending on the environment and usage of MLServer. The CVSS score of 5.3 reflects a medium impact with low to limited confidentiality, integrity, and availability impacts.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since the vendor has not responded or released a fix, users should consider applying manual mitigations such as restricting access to the vulnerable component or isolating MLServer instances until an official patch is available.