dbcve.org
Incorrect AuthorizationWeakness · CWE-863

CVE-2026-43889

MEDIUM · 6.5 CVSS v3.1 Published 2026-05-11
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
71/100
Remediation priority · Elevated
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
Outline is a service that allows for collaborative documentation. Prior to 1.7.0, the shares.create API accepts both collectionId and documentId simultaneously and, when published=false, only verifies read access for each—skipping the "share" permission check. A subsequent shares.update authorizes publication using an OR policy (can share collection OR can share document), so an attacker who holds share permission on one unrelated collection can publish a share that exposes an arbitrary document they cannot legitimately share, making it publicly accessible to unauthenticated users. This vulnerability is fixed in 1.7.0.

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

In Outline versions prior to 1.7.0, the shares.create API accepts both collectionId and documentId parameters simultaneously. When published=false, it only verifies read access for each—skipping the required 'share' permission check. The subsequent shares.update then authorizes publication using an OR policy (can share collection OR can share document), allowing an attacker with share permission on any one collection to publish and expose arbitrary documents they can read but cannot legitimately share, making them publicly accessible to unauthenticated users.

MitigationUpgrade to Outline version 1.7.0 or later, which implements proper share permission verification during both shares.create and shares.update operations.

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
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/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. Check installed Outline version
    Locate the Outline version by checking the application package.json, docker image tag, or running 'outline version' command if available. Compare against 1.7.0.
    Affected if Installed version is prior to 1.7.0
  2. Verify shares.create API accepts both collectionId and documentId
    Review the API endpoint handler for shares.create in the Outline codebase or test the API by sending a request with both collectionId and documentId parameters set.
    Affected if The API accepts both parameters simultaneously without validation error
  3. Check share permission enforcement on shares.create
    Examine the authorization logic in shares.create to verify whether it checks for 'share' permission when published=false. Look for missing permission validation when both collectionId and documentId are provided.
    Affected if The shares.create API only verifies read access without checking share permission when published=false
  4. Check shares.update authorization policy
    Review the authorization logic in shares.update to determine if it uses an OR policy (can share collection OR can share document) for publication authorization.
    Affected if The shares.update uses an OR policy allowing publication if user can share either the collection OR the document
  5. Verify share permission configuration
    Check the share permission settings in Outline admin panel or database to confirm whether users with share permission on any collection can access documents they cannot legitimately share.
    Affected if Share permissions are configured to allow users to publish arbitrary readable documents they lack explicit share permission for

A user is affected if their Outline installation version is prior to 1.7.0 and the shares.create API allows simultaneous collectionId/documentId submission with insufficient permission checks.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to Outline version 1.7.0 or later, which implements proper share permission verification during both shares.create and shares.update operations.

Recommended fix High confidence

1.7.0

  1. 1. Back up your current Outline installation and database before proceeding with the upgrade
  2. 2. Consult the official Outline upgrade documentation for your deployment method (Docker, npm, etc.)
  3. 3. Upgrade Outline to version 1.7.0 or later
  4. 4. Verify the upgrade was successful by checking the application version
  5. 5. Test the shares.create and shares.update API functionality to confirm the authorization fix is working correctly
  6. 6. Review access controls to ensure no unintended shares were created during the vulnerability window

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

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing3.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,750
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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-2026-43889 in production — separate from our analysis above.

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What this is

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