CVE-2025-54461Network attack vector

Unauthenticated guest registration via invitation access-control failure

Published Oct 16, 2025 · Updated Oct 16, 2025

Access control failure in ChatLuck V6.6 R2.0 and earlier allows remote attackers to register an uninvited guest account. NEOJAPAN identifies the guest-user invitation function as the affected locus but intentionally withholds the request-handling and validation details. Guest invitation must be available, and successful exploitation creates a guest-only account whose access remains restricted to invited rooms and contacts.

CVSS severity6.9
Medium
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Access control failure in ChatLuck V6.6 R2.0 and earlier allows remote attackers to register an uninvited guest account. NEOJAPAN identifies the guest-user invitation function as the affected locus but intentionally withholds the request-handling and validation details. Guest invitation must be available, and successful exploitation creates a guest-only account whose access remains restricted to invited rooms and contacts.

The record

CVE
CVE-2025-54461
Published
Oct 16, 2025
Updated
Oct 16, 2025
Vendor
NEOJAPAN Inc.
Product
ChatLuck
Classifications
CWE-1220, T1136
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 16, 2025Record 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=V6.6 R2.0 and earlier

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

NEOJAPAN Inc. · ChatLuckversion=V6.6 R2.0 and earlier

Published CVSS scores

6.9JPCERT/CCCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
5.3JPCERT/CCCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1220Insufficient Granularity of Access Control
T1136Create Account

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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