CVE-2026-93839: ModelTC LightLLM · Missing Authentication
Affects ModelTC LightLLMSource CVE Database V5
Not known to be exploited · CVSS 9.3 Critical.
Data as of 2 Nov 2026, 10:58 UTC
- EPSS
- 0.7% chance of exploitation in 30 days – higher than 55% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 18 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| ModelTCLightLLM | Affected
| Fixed in– |
GitHubLightLLMpkg:github/LightLLMOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until an official fix is available, restrict access to the /pd_register WebSocket endpoint and monitor for suspicious activity related to node registration.
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.
References
- github.com/ModelTC/LightLLM/issues/1576 (opens in a new tab)
- github.com/ModelTC/LightLLM (opens in a new tab)
- github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/api_http_pd.py (opens in a new tab)
- github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/httpserver_for_pd_master/manager.py (opens in a new tab)
- github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/httpserver_for_pd_master/manager.py (opens in a new tab)
- github.com/ModelTC/lightllm/blob/v1.2.0/lightllm/server/api_http.py (opens in a new tab)
- vulncheck.com/advisories/lightllm-through-1.2.0-missing-authentication-in-pd-master-pd-register-websocket-endpoint (opens in a new tab)