Description
BentoML is a Python library for building online serving systems optimized for AI apps and model inference. Prior to 1.4.38, the Dockerfile generation function generate_containerfile() in src/bentoml/_internal/container/generate.py uses an unsandboxed jinja2.Environment with the jinja2.ext.do extension to render user-provided dockerfile_template files. When a victim imports a malicious bento archive and runs bentoml containerize, attacker-controlled Jinja2 template code executes arbitrary Python directly on the host machine, bypassing all container isolation. This vulnerability is fixed in 1.4.38.
Affected products
bentoml: bentoml
References1
- github.com/bentoml/BentoML/security/advisories/GHSA-v959-cwq9-7… ExploitVendor Advisory
Metrics
- CVSS 3.1
-
9.6
CRITICAL
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 35 · as of 12 November 2026
- CWE
- CWE-1336
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.