CVE-2026-43886

HIGH

Outline: OAuth Scope Validation Logic Error Allows Privilege Escalation to Wildcard API Access

Title source: cna
STIX 2.1

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.

References (1)

Core 1
Core References

Scores

CVSS v3 8.2
EPSS 0.0021
EPSS Percentile 11.3%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-269
Status published
Products (1)
outline/outline >= 0.84.0, < 1.7.0
Published May 11, 2026
Tracked Since May 12, 2026