CVE-2026-57205: Microsoft Simplechat

Medium severity, CVSS 4.3. EPSS: 0.9% chance of exploitation in the next 30 days.

SimpleChat is a secure AI conversation application with personal and group workspaces for document-grounded interactions. Prior to 0.241.203, the authenticated GET /api/user/info/<user_id> and GET /api/user/profile-image/<user_id> endpoints in application/single_app/route_backend_users.py accepted a caller-supplied user_id and read the matching Cosmos DB user-settings document without object-level authorization, allowing a low-privilege authenticated user to retrieve another user's email address, display name, and profile image. This issue is fixed in version 0.241.203.

Affected products

• Microsoft Simplechat: before 0.241.203 (fixed in 0.241.203)

Published 2026-07-16. Last modified 2026-07-16.