CVE-2026-90919

LightLLM through 1.2.0 Unauthenticated Remote Code Execution via Config Server Pickle Deserialization

Published Sep 14, 2026 CVSS 4.0 · 9.3 Critical EPSS 1.1% KEV · Not listed

Description

LightLLM through 1.2.0 contains a remote code execution vulnerability in the Config Server's unauthenticated /visual_register WebSocket endpoint that passes the first client frame directly to pickle.loads(). Attackers can reach the Config Server port and send a malicious serialized payload with a __reduce__ method to execute arbitrary code with Config Server process privileges.

Analysis

Technical impact

LightLLM versions through 1.2.0 are vulnerable to unauthenticated remote code execution via, which directly passes the first client frame to pickle.loads(). The endpoint accepts a maliciously crafted payload containing a __reduce__ method, enabling an attacker to execute arbitrary code with the same privileges as the Config Server process. This flaw represents a classic unsafe deserialization vulnerability (CWE‑502) that permits an attacker to compromise the entire system running LightLLM.

Affected Systems

ModelTC LightLLM 1.2.0 and earlier versions are affected. No specific patch version is listed in the data; the issue is resolved in releases newer than 1.2.0.

Risk and Exploitability

The vulnerability scores 9.3 on the CVSS scale, indicating critical impact. EPSS score is 1%, and the vulnerability is not listed in the CISA KEV catalog. The attack vector is network‑based; an attacker must reach the Config Server port. The design of the endpoint exposes it to unauthenticated users, making exploitation likely in any environment where the port is reachable and the endpoint remains active.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

ModelTC

LightLLM

unaffected

Version	Status	Constraints
`0`	affected	≤ 1.2.0

No data.

Vendor Product Versions

Modeltc

Lightllm

Version	Status	Scheme	Platform
`[0,1.2.0]`	affected	semver	—

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Upgrade LightLLM to the latest release that has secured the /visual_register endpoint against unsafe pickle deserialization.
Configure firewall rules to restrict access to the Config Server port so that only trusted hosts can communicate with it.
If an immediate upgrade is not possible, temporarily disable the /visual_register WebSocket endpoint or reconfigure the server to require authentication before processing frames on that endpoint.

Generated by OpenCVE AI on September 21, 2026 at 00:43 UTC.

Tracking

Advisories

No advisories available

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: 1.1% (1.086% probability within 30 days)

Exploitation poc

Automatable yes

Technical Impact total

References

Link	Providers
https://github.com/ModelTC/LightLLM/blob/v1.2.0/lightllm/server/config_server/api_http.py#L79-L86
https://github.com/ModelTC/LightLLM/issues/1563
https://github.com/ModelTC/lightllm
https://www.vulncheck.com/advisories/lightllm-through-1.2.0-unauthenticated-remote-code-execution-via-config-server-pickle-deserialization

History

Sep 14, 2026 9:00 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}`

Sep 14, 2026 1:15 PM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Modeltc Modeltc lightllm
Vendors & Products		Modeltc Modeltc lightllm

Sep 14, 2026 11:45 AM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		LightLLM through 1.2.0 contains a remote code execution vulnerability in the Config Server's unauthenticated /visual_register WebSocket endpoint that passes the first client frame directly to pickle.loads(). Attackers can reach the Config Server port and send a malicious serialized payload with a __reduce__ method to execute arbitrary code with Config Server process privileges.
Title		LightLLM through 1.2.0 Unauthenticated Remote Code Execution via Config Server Pickle Deserialization
Weaknesses		CWE-502
References		https://github.com/ModelTC/LightLLM/blob/v1.2.0/lightllm/server/config_server/api_http.py#L79-L86 https://github.com/ModelTC/LightLLM/issues/1563 https://github.com/ModelTC/lightllm https://www.vulncheck.com/advisories/lightllm-through-1.2.0-unauthenticated-remote-code-execution-via-config-server-pickle-deserialization
Metrics		cvssV3_1 `{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}` cvssV4_0 `{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}`