Open-Source Communications Platform Vulnerability in Rocket.Chat

CVE-2026-45689

What is CVE-2026-45689?

Rocket.Chat, a widely used open-source communications platform, is susceptible to a security flaw that allows an unauthenticated attacker to obtain valid OAuth access tokens. This attack can be executed by sending a crafted HTTP POST request with specific MongoDB query operators to the /oauth/token endpoint. The lack of validation of grant parameters enables the attacker to exploit the OAuth2 server's functionality, bypassing traditional authorization checks. By sequentially querying the oauth_access_tokens collection, an attacker can retrieve access tokens for all users, including those with admin privileges, thereby compromising sensitive API operations. This vulnerability has been addressed in the latest updates of Rocket.Chat, ensuring the integrity and security of user data.

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