8.2
HIGH CVSS 3.1
CVE-2026-43886
Outline: OAuth Scope Validation Logic Error Allows Privilege Escalation to Wildcard API Access
Description

Outline is a service that allows for collaborative documentation. From 0.84.0 to 1.6.1, a logic error in OAuthInterface.validateScope() uses Array.some() to validate requested OAuth scopes, causing the function to accept the entire scope array if any single scope is valid. An attacker can smuggle the wildcard * scope by requesting scope=read *, escalating a read-only OAuth token to full unrestricted API access including write, delete, and admin operations. 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-2026-43886 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 HIGH [email protected]
CVSS 3.1 HIGH MITRE-CVE
Solution
Update Outline to version 1.7.0 or later to fix the OAuth scope validation logic error.
  • Update Outline to version 1.7.0 or later.
  • Review OAuth scope configurations.
  • Limit wildcard scope usage.
  • Monitor API access logs.
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-2026-43886.

URL Resource
https://github.com/outline/outline/security/advisories/GHSA-7732-6qrg-wjf4
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-43886 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-2026-43886 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-2026-43886 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-43886 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. From 0.84.0 to 1.6.1, a logic error in OAuthInterface.validateScope() uses Array.some() to validate requested OAuth scopes, causing the function to accept the entire scope array if any single scope is valid. An attacker can smuggle the wildcard * scope by requesting scope=read *, escalating a read-only OAuth token to full unrestricted API access including write, delete, and admin operations. This vulnerability is fixed in 1.7.0.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N
    Added CWE CWE-269
    Added Reference https://github.com/outline/outline/security/advisories/GHSA-7732-6qrg-wjf4
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.