{"id":"CVE-2026-93839","published":"2026-09-18T20:17:34.047","lastModified":"2026-09-22T20:55:25.800","description":"LightLLM through 1.2.0 contains an authentication bypass vulnerability in the /pd_register WebSocket endpoint that allows unauthenticated attackers to register arbitrary nodes by supplying crafted JSON without peer address validation. Attackers can disclose full user prompts routed to their socket, trigger denial of service by replacing legitimate nodes, or make the PD Master issue requests to internal network addresses.","cvssScore":9.8,"cvssSeverity":"CRITICAL","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwes":["CWE-306"],"vendors":[],"products":[],"references":[{"url":"https://github.com/ModelTC/LightLLM","tags":[]},{"url":"https://github.com/ModelTC/LightLLM/issues/1576","tags":[]},{"url":"https://github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/api_http.py#L198-L205","tags":[]},{"url":"https://github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/api_http_pd.py#L26-L36","tags":[]},{"url":"https://github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/httpserver_for_pd_master/manager.py#L691-L698","tags":[]},{"url":"https://github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/httpserver_for_pd_master/manager.py#L714-L749","tags":[]},{"url":"https://www.vulncheck.com/advisories/lightllm-through-1.2.0-missing-authentication-in-pd-master-pd-register-websocket-endpoint","tags":[]},{"url":"https://github.com/ModelTC/LightLLM/issues/1576","tags":[]}],"exploitRefs":[{"url":"https://github.com/ModelTC/LightLLM","tags":[]},{"url":"https://github.com/ModelTC/LightLLM/issues/1576","tags":[]},{"url":"https://github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/api_http.py#L198-L205","tags":[]},{"url":"https://github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/api_http_pd.py#L26-L36","tags":[]},{"url":"https://github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/httpserver_for_pd_master/manager.py#L691-L698","tags":[]},{"url":"https://github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/httpserver_for_pd_master/manager.py#L714-L749","tags":[]},{"url":"https://github.com/ModelTC/LightLLM/issues/1576","tags":[]}],"hasPoc":true,"ai":{"summary":"LightLLM through 1.2.0 allows unauthenticated attackers to register arbitrary nodes via the /pd_register WebSocket endpoint, leading to potential full user prompt disclosure, denial of service, or internal network request issues.","exploitability":"Exploitation is relatively straightforward as it requires crafting a JSON payload without peer address validation. Attackers must have WebSocket access to the endpoint.","blast_radius":"If exploited, the impact could be severe, affecting user privacy, system availability, and internal network security.","remediation":"Upgrade to LightLLM 1.2.1 or later.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["auth-bypass","web","websocket","denial-of-service"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-09-27T09:00:30.790Z"}}