CVE-2026-54030: LibreChat: Missing Resource Parameter Validation in MCP OAuth Flow

Published Jun 25, 2026
·
Updated

LibreChat is an enhanced ChatGPT clone that supports multiple AI providers. Prior to 0.8.5, LibreChat's MCP OAuth implementation does not validate that the resource parameter from OAuth Protected Resource metadata (RFC 9728) matches the configured MCP server URL, allowing a malicious MCP server to steal access tokens intended for a legitimate server. This vulnerability is fixed in 0.8.5.

Affected Software

3 affected components
librechat librechat<0.8.5
librechat librechat<=0.8.4
librechat librechat=0.8.5-rc1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade LibreChat to a version that resolves this vulnerability.

    Fixed in 0.8.5

Event History

Jun 25, 2026
CVE Published
via MITRE·03:48 PM
Data Sourced
via MITRE·03:48 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·05:16 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-54030?

The severity of CVE-2026-54030 is high, rated at 8.

2

How do I fix CVE-2026-54030?

To fix CVE-2026-54030, update LibreChat to version 0.8.5 or later.

3

What systems are affected by CVE-2026-54030?

CVE-2026-54030 affects LibreChat versions prior to 0.8.5.

4

What impact does CVE-2026-54030 have on users?

CVE-2026-54030 allows a malicious MCP server to potentially exploit vulnerable OAuth flows.

5

Is there a workaround for CVE-2026-54030?

There are no confirmed workarounds for CVE-2026-54030 other than upgrading to the patched version.

Contact

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