CVE-2026-27905 HIGH

CVE-2026-27905: BentoML has an Arbitrary File Write via Symlink Path Traversal in Tar Extraction

Vendor Bentoml
Product BentoML
Weakness CWE-59
Published March 3, 2026
Last update March 4, 2026

CVSS base score

8.6/10
Attack vector Local
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

What the vulnerability does

01Description

BentoML is a Python library for building online serving systems optimized for AI apps and model inference. Prior to 1.4.36, the safe_extract_tarfile() function validates that each tar member's path is within the destination directory, but for symlink members it only validates the symlink's own path, not the symlink's target. An attacker can create a malicious bento/model tar file containing a symlink pointing outside the extraction directory, followed by a regular file that writes through the symlink, achieving arbitrary file write on the host filesystem. This vulnerability is fixed in 1.4.36.

Key dates

02Disclosure timeline

March 3, 2026 CVE published
March 4, 2026 Record updated