Summaryinfo

A vulnerability was found in 1millionbot Millie Chatbot 3.6.0. It has been classified as critical. Impacted is an unknown function of the file api.1millionbot.com/api/public/conversations/. The manipulation leads to authorization. This vulnerability is traded as CVE-2026-4400. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in 1millionbot Millie Chatbot 3.6.0. This issue affects an unknown code block of the file api.1millionbot.com/api/public/conversations/. The manipulation with an unknown input leads to a authorization vulnerability. Using CWE to declare the problem leads to CWE-639. The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Insecure Direct Object Reference (IDOR) vulnerability in 1millionbot Millie chat that allows private conversations of other users being viewed by simply changing the conversation ID. The vulnerability is present in the endpoint 'api.1millionbot.com/api/public/conversations/' and, if exploited, could allow a remote attacker to access other users private chatbot conversations, revealing sensitive or confidential data without requiring credentials or impersonating users. In order for the vulnerability to be exploited, the attacker must have the user's conversation ID.

The weakness was shared by David Utón Amaya. It is possible to read the advisory at incibe.es. The identification of this vulnerability is CVE-2026-4400 since 03/18/2026. The exploitation is known to be difficult. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 03/31/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• Chat Software

Vendor

• 1millionbot

Name

• Millie Chatbot

Version

• 3.6.0

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

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