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Millie ChatbotApplication · 1millionbot

CVE-2026-4400

MEDIUM · 6.5 CVSS v3.1 Published 2026-03-31
Fix available
A fix is available. Upgrade to 3.6.0 or later.
See remediation →
74/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

An IDOR vulnerability in the api.1millionbot.com/api/public/conversations/ endpoint allows unauthenticated attackers to access private chatbot conversations by manipulating the conversation ID parameter. The API fails to validate that the requesting user owns the requested conversation, enabling unauthorized cross-user data access.

MitigationImplement proper authorization checks to verify user ownership before returning conversation data, combined with rate limiting to deter enumeration attacks.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Millie ChatbotApplication
Affected:< 3.6.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Millie Chatbot version
    Locate the chatbot installation and identify the version number from the application metadata, configuration files, or admin panel. Common locations include package.json, version info in admin settings, or the chatbot's about/help section.
    Affected if The installed version is below 3.6.0 (any version starting with 3.5.x or earlier)
  2. Verify API endpoint exposure
    Check if your Millie Chatbot installation is configured to communicate with api.1millionbot.com. Review network logs, proxy configurations, or integration settings to see if outbound calls to this domain are occurring.
    Affected if Your chatbot makes API calls to api.1millionbot.com and the endpoint /api/public/conversations/ is reachable from your deployment
  3. Test conversation enumeration
    If you have access to a conversation ID (from logs, prior API calls, or chat session data), attempt a GET request to api.1millionbot.com/api/public/conversations/{conversation_id} without authentication headers or session tokens.
    Affected if The API returns conversation data for a conversation ID that was not created by the requesting context, indicating missing ownership validation
  4. Review API authentication configuration
    Examine your chatbot's API client configuration, API keys, or authentication tokens stored in your deployment. Check whether the /api/public/conversations/ endpoint is documented as a public endpoint (no auth required).
    Affected if The endpoint is configured as publicly accessible or accepts requests without validating user ownership of the requested conversation

You are affected if you are running Millie Chatbot version 3.5.x or earlier and your installation exposes the api.1millionbot.com API, allowing unauthenticated or unauthorized access to conversation data via IDOR.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 3.6.0 or later
Fixed in 3.6.0
Interim mitigation

Implement proper authorization checks to verify user ownership before returning conversation data, combined with rate limiting to deter enumeration attacks.

Recommended fix High confidence

3.6.0

  1. 1. Identify the current version of Millie Chatbot deployed in your environment
  2. 2. If the current version is below 3.6.0, plan for an upgrade to version 3.6.0 or later
  3. 3. Before upgrading, backup the current configuration and data
  4. 4. Upgrade Millie Chatbot to version 3.6.0
  5. 5. After upgrade, verify that the API endpoint 'api.1millionbot.com/api/public/conversations/' properly enforces authorization checks
  6. 6. Test that users can only access their own conversations and that changing the conversation ID no longer allows unauthorized access

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Millie Chatbot Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-4400 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data