Authorization Bypass (IDOR)Weakness · CWE-639

CVE-2026-40784

HIGH · 8.1 CVSS v3.1 Published 2026-04-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
87/100
Remediation priority · High
Remotely reachable 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
Authorization Bypass Through User-Controlled Key vulnerability in Mahmudul Hasan Arif FluentBoards fluent-boards allows Exploiting Incorrectly Configured Access Control Security Levels.This issue affects FluentBoards: from n/a through <= 1.91.2.

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 · moderate confidence

This is an Authorization Bypass Through User-Controlled Key vulnerability in FluentBoards <= 1.91.2. Attackers can manipulate a user-controlled key (such as an ID or parameter) to access resources or functionality belonging to other users due to incorrectly configured access control security levels.

MitigationApply the vendor patch when available. Until then, implement additional server-side authorization checks on all sensitive operations and verify that user-controlled keys properly validate ownership or permissions before granting access.

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

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
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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. Determine installed FluentBoards version
    Check the application version in the software itself (typically found in the UI footer, an /about endpoint, or version file in the installation directory)
    Affected if The installed version is 1.91.2 or lower
  2. Identify API endpoints accepting user-controlled keys
    Review application API routes or controller definitions to locate endpoints that accept ID parameters, such as board IDs, item IDs, or record identifiers in the request
    Affected if The application exposes endpoints that accept user-controlled identifiers without explicit ownership validation
  3. Test for broken access control on sensitive operations
    Using an authenticated account, manipulate identifier parameters (such as IDs in URLs or request bodies) in API calls to access resources belonging to a different user
    Affected if Requests with another user's identifiers are successfully processed without proper authorization failures
  4. Verify authorization logic for resource access
    Inspect the application source code or configuration to confirm that access control checks validate ownership/permissions before granting resource access
    Affected if Authorization logic is missing or incorrectly validates user-controlled keys before allowing access to sensitive data

A user is affected if FluentBoards version 1.91.2 or lower is installed and the application processes user-controlled keys in requests without proper ownership validation.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor patch when available. Until then, implement additional server-side authorization checks on all sensitive operations and verify that user-controlled keys properly validate ownership or permissions before granting access.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,640
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Scan for this in your stack

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dbcve dependency scanner

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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-2026-40784 in production — separate from our analysis above.

No notes yet

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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
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