{"id":"CVE-2026-59823","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-59823","generatedAt":"2026-10-28T09:27:24.857Z","title":"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…","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.","published":"2026-09-16T19:17:21.000Z","lastModified":"2026-09-30T17:43:24.000Z","status":"Awaiting Analysis","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"4.0","score":5.3,"severity":"MEDIUM","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-918"],"affected":[],"epss":{"score":0.00439,"percentile":0.37969,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.44%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/BerriAI/litellm/commit/47214be317f45a2d2ac08258362e0481411eb427","source":"security-advisories@github.com"},{"url":"https://github.com/BerriAI/litellm/pull/25827","source":"security-advisories@github.com"},{"url":"https://github.com/BerriAI/litellm/security/advisories/GHSA-hx8v-g79f-8w5f","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-59823","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}