CVE-2026-111707

99AI through 4.3.0 contains an insecure direct object reference vulnerability that allows unauthenticated attackers to read other users' chat messages because querySingleChat lacks an owner check. Attackers can send a fingerprint header to obtain a visitor JWT and iterate sequential chatId values to retrieve other users' message content and task data.

An unauthenticated attacker can access other users' private chat messages, constituting a serious privacy breach and potentially leading to leakage of sensitive information. This may result in identity theft or blackmail.

Update 99AI to a version later than 4.3.0 that fixes this vulnerability. Until then, consider implementing additional access controls for chat endpoints.