CVE-2026-43886
CWE-269Published: May 11, 2026· Updated: May 12, 2026
Official 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.
Technical Analysis
CVE-2026-43886 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.
A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 8.2.
The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.
CVSS v3.1 Vector Breakdown
Exploit & PoC Resources
All References (2)
Quick Facts
Related CVEs (CWE-269)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-43886 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts