CVE-2026-42461Network attack vector

Unauthenticated secret disclosure via unsecured template endpoints

Published May 9, 2026 · Updated May 9, 2026

Missing authorization in Arcane before 1.18.0 allows remote attackers to read stored Compose templates and environment secrets. RegisterTemplates omits Security requirements on four Huma GET operations, so the auth bridge passes requests without checking a token and returns Content and EnvContent verbatim. Any network client that can reach the Arcane API needs no account or token and can enumerate internal services and recover stored credentials.

CVSS severity8.7
High
EPSS probability1.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authorization in Arcane before 1.18.0 allows remote attackers to read stored Compose templates and environment secrets. RegisterTemplates omits Security requirements on four Huma GET operations, so the auth bridge passes requests without checking a token and returns Content and EnvContent verbatim. Any network client that can reach the Arcane API needs no account or token and can enumerate internal services and recover stored credentials.

The record

CVE
CVE-2026-42461
Published
May 9, 2026
Updated
May 9, 2026
Vendor
Arcane
Product
Arcane
Classifications
CWE-862, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 9, 2026CVE publishedPublication date reported by the CVE source.
  2. May 9, 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=< 1.18.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Arcane · Arcaneversion=< 1.18.0

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
8.7GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-862Missing Authorization
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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