Prompt disclosure via unauthenticated node registration
Published Sep 18, 2026 · Updated Sep 18, 2026
Authentication bypass in ModelTC LightLLM 1.2.0 and earlier allows remote attackers to register arbitrary PD Master nodes. The /pd_register WebSocket handler accepts crafted JSON and trusts the supplied node and peer address without authenticating or validating the connection source. A network-reachable PD Master in disaggregated mode can route prompts to the attacker, replace legitimate nodes, or issue requests to internal addresses.
Summary
What happened
Authentication bypass in ModelTC LightLLM 1.2.0 and earlier allows remote attackers to register arbitrary PD Master nodes. The /pd_register WebSocket handler accepts crafted JSON and trusts the supplied node and peer address without authenticating or validating the connection source. A network-reachable PD Master in disaggregated mode can route prompts to the attacker, replace legitimate nodes, or issue requests to internal addresses.
The record
- CVE
- CVE-2026-93839
- Published
- Sep 18, 2026
- Updated
- Sep 18, 2026
- Vendor
- ModelTC
- Product
- LightLLM
- Classifications
- T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 18, 2026CVE publishedPublication date reported by the CVE source.
- Sep 18, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <=1.2.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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