Improper Access Control in Outline Service by Outline
CVE-2026-43889

6.5MEDIUM

Key Information:

Vendor

Outline

Status
Outline
Vendor
CVE Published:
11 May 2026

What is CVE-2026-43889?

The Outline service, a platform for collaborative documentation, experienced a vulnerability where the shares.create API enabled improper access control. Before version 1.7.0, this API allowed simultaneous input of collectionId and documentId without adequately verifying the user's permission to share the document. If the publication flag is set to false, the system only checks read access, bypassing critical share permission validation. Consequently, an attacker with share rights to an unrelated collection could exploit this flaw, potentially publishing a share that exposes unauthorized documents, making them accessible to unauthenticated individuals. This vulnerability has been addressed in version 1.7.0.

Affected Version(s)

outline < 1.7.0

References

https://github.com/outline/outline/security/advisories/GH...
x_refsource_CONFIRM

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.