CVE-2026-4400

CVE-2026-4400 is an Insecure Direct Object Reference (IDOR) vulnerability affecting the 1millionbot Millie chat application. This flaw allows an unauthenticated remote attacker to view other users' private chatbot conversations by manipulating conversation IDs in the API endpoint, potentially exposing sensitive data. Rated 7.0 High severity, exploitation requires high attack complexity as the attacker must first obtain a valid conversation ID, but no user interaction or privileges are needed. There is currently no evidence of active exploitation, public exploit code, or significant community discussion surrounding this vulnerability.