CVE-2026-59823

5.3 MEDIUM 0.4% exploit odds Fix listed Disclosure Network gear

What it is

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.

At a glance

Exploitability: Can be exploited over the network with a low-privilege account. Limited direct impact.
Exploit odds: 0.4% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-09-16 19:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-09-30 17:43 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.4% in the next 30 days (EPSS).
Severity: 5.3 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-09-16 19:17 UTC
Last modified: 2026-09-30 17:43 UTC
Exploit probability: 0.4% · EPSS, next 30 days
Weakness: CWE-918 · Server-side request forgery
Record status: Awaiting Analysis

Attack profile CVSS 4.0 · 5.3

Attack vector: Network
Complexity: Low
Attack requirements: None
Privileges needed: Low
User interaction: None
Confidentiality: Low
Integrity: None
Availability: None

Raw 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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-59823.md and follow it. Check whether this project is affected by CVE-2026-59823. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record