Authorization Bypass (IDOR)Weakness · CWE-639

CVE-2025-51869

HIGH · 7.5 CVSS v3.1 Published 2025-07-21
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
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 Liner thru 2025-06-03 allows attackers to gain sensitive information via crafted space_id, thread_id, and message_id parameters to the v1/space/{space_id}/thread/{thread_id}/message/{message_id} endpoint.

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 Insecure Direct Object Reference (IDOR) vulnerability in the Liner application. The v1/space/{space_id}/thread/{thread_id}/message/{message_id} endpoint fails to properly validate user authorization before returning message data. Attackers can manipulate the space_id, thread_id, and message_id parameters to access sensitive messages they are not authorized to view.

MitigationImplement proper authorization checks at the endpoint to verify the authenticated user has permission to access the requested space, thread, and message before returning any data. Additionally, consider implementing indirect references (mapping internal IDs to random/temporary identifiers) to prevent enumeration.

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

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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. Identify if Liner application is deployed
    Review your application inventory or running services to confirm the Liner product is in use. Check for processes, containers, or services named 'liner' or documentation referencing Liner.
    Affected if Liner application is present in your environment
  2. Locate the affected API endpoint
    Review API documentation, route definitions, or network traffic logs for requests to endpoints matching the pattern v1/space/{space_id}/thread/{thread_id}/message/{message_id}. Use grep or log search tools to find instances of this path structure.
    Affected if The v1/space/*/thread/*/message/* endpoint is exposed and accessible in your environment
  3. Verify authentication is required for the endpoint
    Attempt unauthenticated requests to the endpoint using a tool like curl or Burp Suite. Observe whether the API returns a 401 or 403 status code, or requires a valid authentication token.
    Affected if The endpoint can be accessed without valid authentication credentials
  4. Test for IDOR by accessing messages from different spaces
    Log in as User A with access to one space. Using the affected endpoint, modify the space_id, thread_id, or message_id parameters to reference resources belonging to a different space or thread that User A should not have access to. Check if the API returns the message data.
    Affected if The API returns message data for resources the authenticated user does not own or have permission to access
  5. Check authorization logs or middleware
    Review application logs, API gateway logs, or authorization middleware code for the affected endpoint. Look for authorization validation logic that checks if the user owns or has access to the requested space_id, thread_id, and message_id before returning data.
    Affected if No explicit ownership or permission check is performed before returning message content

If the Liner application exposes the v1/space/{space_id}/thread/{thread_id}/message/{message_id} endpoint and allows authenticated users to retrieve messages from spaces, threads, or messages they do not own, the environment is affected by this IDOR vulnerability.

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

Implement proper authorization checks at the endpoint to verify the authenticated user has permission to access the requested space, thread, and message before returning any data. Additionally, consider implementing indirect references (mapping internal IDs to random/temporary identifiers) to prevent enumeration.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA3.0 h
18.0 hours of engineering $3,180
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,088.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-51869 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2025-51869 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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