LightLLM through 1.2.0 Missing Authentication in PD Master /pd_register WebSocket Endpoint
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-306.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-93839
- 2026-10-03 Alias added: GHSA-644q-7756-5g89
References
Other 6
- GitHub Issue #1576
- https://github.com/ModelTC/LightLLM
- 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#L714-L749
- 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/api_http.py#L198-L205
More ModelTC vulnerabilities
- TI-2026-65681 LightLLM through 1.2.0 Unauthenticated Remote Code Execution via Visual-Only RPyC Service CVSS 4.0CRITICAL 9.3
- TI-2026-65562 LightLLM through 1.2.0 Unauthenticated Remote Code Execution via Embed Cache RPyC Service CVSS 4.0CRITICAL 9.3
- TI-2026-65561 LightLLM through 1.2.0 Unauthenticated Remote Code Execution via Router Profiler RPyC Service CVSS 4.0CRITICAL 9.3
- TI-2026-61785 LightLLM through 1.2.0 Unauthenticated Remote Code Execution via Config Server Pickle Deserialization CVSS 4.0CRITICAL 9.3
- TI-2026-21211 LightLLM <= 1.1.0 PD Mode Unsafe Deserialization RCE CVSS 4.0CRITICAL 9.3
- TI-2026-74944 Unauthenticated denial of service in LightLLM via pd_kv_trans_params CVSS 4.0HIGH 8.7
Sources
- CVE-2026-93839 · CVE Program
- CVE-2026-93839 · NVD
- FIRST EPSS
- GHSA-644q-7756-5g89 · GitHub Advisory Database · CC BY 4.0
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