9.8Critical
CVE-2026-93839
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.
What this means for your business
- An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
Not sure if your company is exposed?
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Scoring
- CVSS
- 9.8 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- CVSS v4
- 9.3
- Weakness
- CWE-306
- Assigned by
- disclosure@vulncheck.com
Dates
- Published
- 2026-09-18
- Last modified
- 2026-09-18
- Sources
- NVD
References
- https://github.com/ModelTC/LightLLM
- https://github.com/ModelTC/LightLLM/issues/1576
- https://github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/api_http.py#L198-L205
- https://github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/api_http_pd.py#L26-L36
- https://github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/httpserver_for_pd_master/manager.py#L691-L698
- https://github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/httpserver_for_pd_master/manager.py#L714-L749
- https://www.vulncheck.com/advisories/lightllm-through-1.2.0-missing-authentication-in-pd-master-pd-register-websocket-endpoint