WebSocket API service vulnerability

What happened

Discord through 2026-01-16 allows gathering information about whether a user's client state is Invisible (and not actually offline) because the response to a WebSocket API request includes the user in the presences array (with "status": "offline"), whereas offline users are omitted from the presences array. This is arguably inconsistent with the UI description of Invisible as "You will appear offline." NOTE: a third-party report suggests that this was remediated later in 2026.

Affected versions

WebSocket API service: 0 through 2026-01-16 (custom) Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.