CVE-2026-40610Public exploit

Build-host file disclosure via followed context symlinks

Published May 22, 2026 · Updated May 22, 2026

Information disclosure in BentoML 1.4.38 and earlier allows attackers to copy build-host files into Bento artifacts via malicious symlinks. The build packager in src/bentoml/_internal/bento/bento.py passes matched context paths to shutil.copy with symlink following enabled, so a link resolves outside the context and its target bytes enter the artifact. Exploitation requires a developer or CI system to build attacker-supplied content; exported, pushed, or containerized Bentos can carry exposed host secrets beyond the build machine.

CVSS severity5.5
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in BentoML 1.4.38 and earlier allows attackers to copy build-host files into Bento artifacts via malicious symlinks. The build packager in src/bentoml/_internal/bento/bento.py passes matched context paths to shutil.copy with symlink following enabled, so a link resolves outside the context and its target bytes enter the artifact. Exploitation requires a developer or CI system to build attacker-supplied content; exported, pushed, or containerized Bentos can carry exposed host secrets beyond the build machine.

The record

CVE
CVE-2026-40610
Published
May 22, 2026
Updated
May 22, 2026
Vendor
BentoML
Product
BentoML
Classifications
CWE-59, T1005
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 22, 2026CVE publishedPublication date reported by the CVE source.
  2. May 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.4.39

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

BentoML · BentoMLversion=< 1.4.39

Published CVSS scores

5.5GitHubCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-59Improper Link Resolution Before File Access ('Link Following')
T1005Data from Local System

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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