Executive brief
Rocket.Chat is a communications platform used for team collaboration and messaging. A security flaw in its login system allows an attacker to remotely force users out of their accounts without needing a password. By repeatedly triggering this flaw, an attacker can prevent employees from staying logged in, effectively causing a total service outage for the organization.
Technical details
A missing authorization/signature verification vulnerability exists in Rocket.Chat's SAML Service Provider (SP) implementation. The application processes inbound SAML LogoutRequest messages without verifying their digital signatures. An unauthenticated remote attacker can craft a malicious LogoutRequest using a target's SAML NameID (often their email address) and submit it to the logout endpoint. This results in the immediate destruction of the victim's session. The attack can be automated to target all SAML-authenticated users, leading to a persistent Denial of Service (DoS). The issue is resolved in versions 8.5.0, 8.4.1, 8.3.3, 8.2.3, 8.1.4, 8.0.5, 7.13.7, and 7.10.11.
Affected products
- RocketChat Rocket.Chat < 8.5.0, < 8.4.1, < 8.3.3, < 8.2.3, < 8.1.4, < 8.0.5, < 7.13.7, < 7.10.11
Timeline
- 2026-05-14: advisory: GitHub Security Advisory published
- 2026-06-24: disclosed: CVE published to NVD