---
id: CVE-2026-59823
title: >-
  LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native)
  format
summary: >-
  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_req…
severity: medium
cvss: 5.3
cvssVector: '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'
cwe:
  - CWE-918
vendor: BerriAI
product: litellm
affected:
  - litellm < 1.83.9
patched:
  - litellm 1.83.9
published: '2026-09-16'
updated: '2026-09-17'
sourceUpdated: '2026-09-17T16:17:32.037'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-59823'
references:
  - url: >-
      https://github.com/BerriAI/litellm/commit/47214be317f45a2d2ac08258362e0481411eb427
    label: security-advisories@github.com
  - url: 'https://github.com/BerriAI/litellm/pull/25827'
    label: security-advisories@github.com
  - url: 'https://github.com/BerriAI/litellm/security/advisories/GHSA-hx8v-g79f-8w5f'
    label: security-advisories@github.com
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-59823'
  - url: 'https://github.com/advisories/GHSA-hx8v-g79f-8w5f'
  - url: 'https://github.com/BerriAI/litellm'
tags:
  - nvd
  - cve.org
  - ghsa
  - pip
  - osv
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-17T15:07:39.533665Z'
cvssSource: cna
aliases:
  - GHSA-hx8v-g79f-8w5f
ecosystem: pip
ingestedAt: '2026-09-16T19:02:30.730Z'
epss: 0.00439
epssPercentile: 0.35535
---

## Overview

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

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-59823)

Affected packages:

- `litellm <= 1.83.8`

Patched in:

- `litellm 1.83.9`

Source: https://github.com/advisories/GHSA-hx8v-g79f-8w5f