CVE-2026-27905 PUBLISHED

BentoML has an Arbitrary File Write via Symlink Path Traversal in Tar Extraction

Assigner: GitHub_M
Reserved: 24.02.2026 Published: 03.03.2026 Updated: 03.03.2026

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.

Metrics

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
CVSS Score: 8.6

Product Status

Vendor bentoml
Product BentoML
Versions
  • Version < 1.4.36 is affected

References

Problem Types

  • CWE-59: Improper Link Resolution Before File Access ('Link Following') CWE