VulnerabilityPublished 16 Oct 2025

CVE-2025-54461: NEOJAPAN ChatLuck · Insufficient Granularity of Access Control

Affects NEOJAPAN ChatLuckSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.0 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 25% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 16 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
NEOJAPAN Inc. ChatLuck	Affected <=6.6	Fixed in–

AI-suggested

Monitor NEOJAPAN Inc. official channels for patches addressing CVE-2025-54461 and apply updates promptly once released.
Temporarily disable or restrict the guest user invitation feature in ChatLuck to prevent unauthorized registrations.
Implement strict monitoring and logging of guest user account creation and activity to detect suspicious behavior early.
Enforce network-level access controls such as IP whitelisting or VPN requirements for accessing ChatLuck, limiting exposure to external attackers.
Conduct regular audits of guest user permissions and remove any unnecessary or inactive guest accounts.
Educate internal users about the risks of sharing sensitive information in guest-accessible channels and encourage use of secure communication practices.
If possible, integrate ChatLuck with identity and access management (IAM) solutions to enhance guest user verification and control.
Review and strengthen overall access control policies within the organization’s communication platforms to ensure least privilege principles are enforced.

Description

ChatLuck contains an insufficient granularity of access control vulnerability in Invitation of Guest Users. If exploited, an uninvited guest user may register itself as a guest user.

Impact

For European organizations, the primary impact of CVE-2025-54461 is the potential unauthorized access by uninvited guest users to internal communication channels within ChatLuck. This could lead to exposure of sensitive corporate information, strategic discussions, or personal data shared in guest-accessible areas. While the vulnerability does not allow modification or disruption of data (no integrity or availability impact), the confidentiality breach could have reputational and compliance consequences, especially under GDPR regulations. Industries relying heavily on secure internal communications, such as finance, healthcare, government, and critical infrastructure, may face increased risk. The ease of exploitation without authentication means that attackers can attempt access from external networks, increasing the threat landscape. Although no known exploits exist currently, the vulnerability could be targeted in the future, particularly by threat actors seeking intelligence or insider information. European organizations should consider the risk of data leakage and unauthorized presence within their communication platforms and implement compensating controls until patches are available.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 16 Oct 2025, 09:15 UTC

Technical details

References

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