CVE-2026-27905

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.

CVSS 4.0

8.6CVSS: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 3.1

7.8CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS

0.3% chance of exploitation in the next 30 days; higher than 18% of CVEs (scores of 2026-10-25)

CWE

CWE-59

Published

2026-03-03

Modified

2026-10-07

Record from

the NVD, synced 2026-10-19

Affected

• bentoml:bentoml

Packages (OSV)

References

• https://github.com/bentoml/BentoML/commit/4e0eb007765ac04c7924220d643f264715cc9670
• https://github.com/bentoml/BentoML/security/advisories/GHSA-m6w7-qv66-g3mf

Check your stackJSON