CVE-2026-96679

Three critical authentication bypass flaws in Bisheng (open-source LLM DevOps platform) allow unauthenticated attackers to gain full admin control and expose cross-user data.

Technical Breakdown: - CVE-2026-96679 (Legacy SSO Bypass): The POST /user/sso endpoint accepts arbitrary usernames in JSON payloads and issues a valid JWT with zero authentication checks. If the username doesn't exist, the system auto-registers it. If that new account matches the configured admin username or is the first user, it gets super-admin privileges. - IDOR Vulnerability: Exposes cross-user workflow data via insecure direct object references. - Pre-2.5.0 Missing Access Controls: Authenticated attackers can abuse cross-user LLM credentials and access hardcoded credentials due to missing service-layer authorization checks.

Attack Chain: An unauthenticated attacker sends a crafted POST to /user/sso with the admin username → receives a super-admin JWT → full platform compromise. Authenticated users can then pivot to steal LLM credentials and sensitive data.

Defense: Immediately upgrade to Bisheng 2.5.0 or later. If immediate patching isn't possible, restrict network access to the SSO endpoint via WAF rules or reverse proxy allowlisting, and audit for any unexpected admin accounts.

Source: https://kb.cert.org/vuls/id/166125