mediumCVSS 5.3NVD status: Awaiting Analysis

CVE-2026-59823

LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format.

ComponentLiteLLM
Severitymedium (CVSS 5.3)
CVSS vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Published (NVD)2026-09-16
Last modified2026-09-30
Affected versions
< 1.83.9
read from the advisory text: NVD has not published CPE data yet
Fixed in1.83.9
WeaknessCWE-918
CISA KEVnot listed

NVD 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.

Does CVE-2026-59823 hit the version you run?Paste your docker-compose.yml, requirements.txt or package.json. The scanner checks your pinned versions against this CVE and every other one we track for LiteLLM.
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What to do

  • Upgrade LiteLLM to 1.83.9 or later.
  • Do not expose the component's API or UI to the internet without authentication in front of it.

Sources

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