CVE-2025-68663: Outline has a suspended user authentication bypass via WebSocket connections

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-02-11 · updated 2026-06-17
Weakness: CWE-287

Description

Outline is a service that allows for collaborative documentation. Prior to 1.1.0, a vulnerability was found in Outline's WebSocket authentication mechanism that allows suspended users to maintain or establish real-time WebSocket connections and continue receiving sensitive operational updates after their account has been suspended. This vulnerability is fixed in 1.1.0.

Affected products

outline: before 1.1.0 — fixed in 1.1.0

How to fix

Upgrade to a fixed version: outline 1.1.0. Check the vendor advisory for mitigations.

References

https://github.com/outline/outline/releases/tag/v1.1.0
https://github.com/outline/outline/security/advisories/GHSA-mx2c-3g2x-5m9m

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