CVE-2026-54033 LibreChat: SSRF via User-Provided Custom Endpoint baseURL — no private IP validation on user-configured API base URLs

High 7.7 Published 25 Jun 2026 Updated 25 Jun 2026

Authenticated users can exploit missing SSRF validation in custom API endpoint configuration to access internal network resources.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-54033?

CVE-2026-54033 is a high-severity server-side request forgery vulnerability in Librechat Librechat, published on 25 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

LibreChat is an enhanced ChatGPT clone that supports multiple AI providers. Prior to 0.8.4-rc1, LibreChat allows users to configure custom OpenAI-compatible API endpoints by setting a baseURL. This URL is used to construct HTTP requests without any SSRF validation — no private IP check, no scheme restriction, no DNS pinning. An authenticated user can set baseURL to internal network addresses. This vulnerability is fixed in 0.8.4-rc1.

Weakness: CWE-918

Which versions are affected by CVE-2026-54033?

It affects 1 product.

Products include Librechat Librechat.

How do I fix CVE-2026-54033?

No fix has been published for CVE-2026-54033 yet. Limit exposure of the affected software until one is available.

Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.

Is CVE-2026-54033 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54033 exists.

All Librechat Librechat vulnerabilities

Sources

Also known as GHSA-gc9r-88c3-7qhq.