6.5
MEDIUM CVSS 3.1
CVE-2026-43889
Outline: Unauthorized Document Publication via Mixed collectionId+documentId Share
Description

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.

INFO

Published Date :

May 11, 2026, 10:22 p.m.

Last Modified :

May 11, 2026, 10:22 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-43889 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
CVSS 3.1 MEDIUM MITRE-CVE
Solution
Update Outline to version 1.7.0 or later to fix authorization bypass.
  • Update Outline to version 1.7.0 or later.
  • Ensure proper sharing permissions are configured.
  • Review access controls for sensitive documents.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-43889.

URL Resource
https://github.com/outline/outline/security/advisories/GHSA-rg4j-pmch-w6pm
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-43889 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-43889 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-43889 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-43889 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    May. 11, 2026

    Action Type Old Value New Value
    Added Description 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.
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
    Added CWE CWE-863
    Added Reference https://github.com/outline/outline/security/advisories/GHSA-rg4j-pmch-w6pm
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.