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TI-2026-29345 Aliases CVE-2026-40610GHSA-mcfx-4vc6-qgxv

BentoML has Information Disclosure in `bentoml build` via symlink traversal in the build context

Priority MEDIUM 58CWE-59Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-59 and the CVSS impact.

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 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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00284 21st percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed BentoML (bentoml): 1.4.39bentoml (PyPI): 1.4.39

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
bentomlBentoMLbefore 1.4.391.4.39Patch availableCNA
—bentoml (PyPI)before 1.4.391.4.39Patch availableGHSA-mcfx-4vc6-qgxv
  • BentoML Vendorbentoml Affected before 1.4.39 Fixed in 1.4.39 Patch available CNA
  • bentoml (PyPI) Vendor— Affected before 1.4.39 Fixed in 1.4.39 Patch available GHSA-mcfx-4vc6-qgxv

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:bentoml:bentoml:*:*:*:*:*:*:*:*before 1.4.39Vulnerablebentoml
  • cpe:2.3:a:bentoml:bentoml:*:*:*:*:*:*:*:* Versions before 1.4.39 Vulnerable ·bentoml

Remediation

  • Fix · CNA BentoML (bentoml) Fixed in 1.4.39
  • Fix · GHSA-mcfx-4vc6-qgxv bentoml (PyPI) Fixed in 1.4.39 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-40610
  2. 2026-10-03 Alias added: GHSA-mcfx-4vc6-qgxv

References

Exploit 1

Patch 1

Advisory 1

Other 2

  • TI-2025-34190 BentoML is Vulnerable to an SSRF Attack Through File Upload Processing CVSS 3.1CRITICAL 9.9
  • TI-2025-23454 Insecure Deserialization leads to RCE in BentoML's runner server CVSS 3.1CRITICAL 9.8
  • TI-2025-20352 BentoML Allows Remote Code Execution (RCE) via Insecure Deserialization CVSS 3.1CRITICAL 9.8
  • TI-2026-27247 BentoML has a Server-Side Template Injection via unsandboxed Jinja2 Environment in Dockerfile generation CVSS 3.1CRITICAL 9.6
  • TI-2026-32312 BentoML: Dockerfile command injection via envs[*].name in bentofile.yaml CVSS 3.1HIGH 8.8
  • TI-2026-32311 BentoML: Dockerfile command injection via docker.base_image CVSS 3.1HIGH 8.8
See all 10 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences