CVE-2026-59823

LiteLLM: Server-side request forgery via the `user_config` request parameter in LiteLLM Proxy

Published Sep 16, 2026 CVSS 4.0 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. Prior to 1.83.9, an authenticated LiteLLM Proxy caller with a valid virtual key can place api_base inside the user_config request body to bypass is_request_body_safe, which blocks top-level api_base and base_url but previously did not inspect or reject user_config. Because user_config constructs the outbound router, the nested destination redirects a server-side request to an internal or external host selected by the caller and can expose endpoints the caller cannot otherwise access. This issue is fixed in version 1.83.9.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-hx8v-g79f-8w5f LiteLLM Proxy has server-side request forgery via the `user_config` request parameter
History
Type Values Removed Values Added
First Time appeared Berriai
Berriai litellm
Vendors & Products Berriai
Berriai litellm
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. Prior to 1.83.9, an authenticated LiteLLM Proxy caller with a valid virtual key can place api_base inside the user_config request body to bypass is_request_body_safe, which blocks top-level api_base and base_url but previously did not inspect or reject user_config. Because user_config constructs the outbound router, the nested destination redirects a server-side request to an internal or external host selected by the caller and can expose endpoints the caller cannot otherwise access. This issue is fixed in version 1.83.9.
Title LiteLLM: Server-side request forgery via the `user_config` request parameter in LiteLLM Proxy
Weaknesses CWE-918
References
Metrics cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 17, 2026, 3:07 PM
Reserved
Jul 7, 2026, 3:00 PM
Status
Awaiting Analysis
Published
Sep 16, 2026, 7:17 PM
Modified
Sep 30, 2026, 5:43 PM