VU#166125: Bisheng has authentication bypass vulnerabilities

Publisher excerpt From CERT/CC Vulnerability Notes

Overview Bisheng contains three vulnerabilities: a pre-authentication account takeover mechanism via a legacy single sign-on (SSO) endpoint; an Insecure Direct Object Reference (IDOR) vulnerability that exposes cross-user workflow data; and prior to version 2.5.0, authenticated attackers could perform cross-user LLM credential abuse and data disclosure due to missing service-layer access checks. Together, these flaws could allow unauthenticated attackers to gain administrative control while enabling authenticated users access to sensitive data and hardcoded credentials. Description Bisheng is an open-source Large Language Model (LLM) application DevOps platform, developed by DataElement, designed to assist in building, managing, and scaling LLMs. CVE-2026-96679 (Legacy SSO Bypass) A vulnerability resides in the legacy SSO endpoint (POST /user/sso). The application processes incoming JSON payloads containing arbitrary usernames and issues a valid JSON Web Token (JWT) without enforcing any form of caller authentication, such as signature verification, shared secrets, or network allowlisting. Furthermore, if the provided username does not exist, the system automatically registers the account. If this newly generated account matches the configured administrative username or is the first user in the system, it is automatically granted super-administrator privileges. CVE-2026-96681 (IDOR Workflow Exposure) There are missing authorization controls across multiple version retri…

Excerpt only, shown with attribution. This content belongs to the original publisher and has not been independently verified by CyberSecurity.pk.