---
id: CVE-2026-40610
title: >-
  BentoML is a Python library for building online serving systems optimized for
  AI apps and model inference
summary: >-
  BentoML is a Python library for building online serving systems optimized for
  AI apps and model inference. In versions 1.4.38 and prior, the build packaging
  workflow follows attacker-controlled symlinks inside the build context and
  copie…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N'
cwe:
  - CWE-59
vendor: bentoml
product: bentoml
affected:
  - bentoml < 1.4.39
patched:
  - bentoml 1.4.39
published: '2026-05-22'
updated: '2026-10-06'
sourceUpdated: '2026-10-06T22:10:00.247'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-40610'
references:
  - url: >-
      https://github.com/bentoml/BentoML/commit/5fb7cd41f92e2a56b45391284cf15b9ac9963a1f
    label: security-advisories@github.com
  - url: 'https://github.com/bentoml/BentoML/releases/tag/v1.4.39'
    label: security-advisories@github.com
  - url: 'https://github.com/bentoml/BentoML/security/advisories/GHSA-mcfx-4vc6-qgxv'
    label: security-advisories@github.com
  - url: 'https://github.com/bentoml/BentoML/security/advisories/GHSA-mcfx-4vc6-qgxv'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-40610'
  - url: 'https://github.com/bentoml/BentoML'
tags:
  - nvd
  - osv
  - pip
epss: 0.00284
epssPercentile: 0.20799
aliases:
  - GHSA-mcfx-4vc6-qgxv
  - PYSEC-2026-2399
ecosystem: pip
ingestedAt: '2026-07-13T18:58:00.551Z'
---

## Overview

BentoML is a Python library for building online serving systems optimized for AI apps and model inference. In versions 1.4.38 and prior, the build packaging workflow follows attacker-controlled symlinks inside the build context and copies the referenced file contents into the generated Bento artifact. If a victim builds an untrusted repository or other attacker-supplied build context, the attacker can place a symlink such as loot.txt -> /tmp/outside-marker.txt or a link to a more sensitive local file. When bentoml build runs, BentoML dereferences the symlink and packages the target file contents into the Bento. The leaked file can then propagate further through export, push, or containerization workflows. An attacker can exfiltrate local files from the build host into the Bento artifact, exposing secrets such as cloud credentials, SSH keys, API tokens, environment files, or other sensitive local configurations. Because Bento artifacts are commonly exported, uploaded, stored, or containerized after build, the leaked file contents can spread beyond the original build machine. This issue has been fixed in version 1.4.39.

## Affected

- `bentoml < 1.4.39`

## Remediation

Upgrade past the affected range:

- `bentoml 1.4.39`

## Package advisory (CVE-2026-40610)

Affected packages:

- `bentoml < 1.4.39`

Patched in:

- `bentoml 1.4.39`

Source: https://osv.dev/vulnerability/GHSA-mcfx-4vc6-qgxv