CVE-2026-43889 MEDIUM

CVE-2026-43889: Outline: Unauthorized Document Publication via Mixed collectionId+documentId Share

Vendor Outline
Product outline
Weakness CWE-863 · Incorrect authorization
Published May 11, 2026
Last update May 12, 2026

CVSS base score

6.5/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality High
Integrity None

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

May 11, 2026 CVE published
May 12, 2026 Record updated