danny-avila LibreChat up to 0.8.3 API Response /api/mcp/servers insertion of sensitive information into sent data

Summaryinfo

A vulnerability classified as problematic has been found in danny-avila LibreChat up to 0.8.3. The impacted element is an unknown function of the file /api/mcp/servers of the component API Response Handler. The manipulation leads to insertion of sensitive information into sent data. This vulnerability is referenced as CVE-2026-44653. Remote exploitation of the attack is possible. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in danny-avila LibreChat up to 0.8.3. It has been rated as problematic. This issue affects some unknown processing of the file /api/mcp/servers of the component API Response Handler. The manipulation with an unknown input leads to a insertion of sensitive information into sent data vulnerability. Using CWE to declare the problem leads to CWE-201. The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor. Impacted is confidentiality. The summary by CVE is:

LibreChat is an enhanced ChatGPT clone that supports multiple AI providers. In versions up to and including 0.8.3, users with only `VIEW` access to an MCP server can retrieve the server's decrypted admin-managed secrets through `GET /api/mcp/servers` and `GET /api/mcp/servers/:serverName`. The returned config includes plaintext values for `apiKey.key` and `oauth.client_secret`. This allows viewers of a shared MCP server to exfiltrate the underlying provider credentials. Version 0.8..4 contains a patch. Other remediations include: never returning decrypted admin-managed secrets to non-owners; redacting apiKey.key and oauth.client_secret from all API responses consider returning only boolean presence indicators for secrets, similar to the auth-values route pattern; and, if owners need to edit configs without re-entering secrets, preserving secrets server-side and returning placeholders instead of plaintext.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-44653 since 05/07/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1592 for this issue.

Upgrading to version 0.8.4 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-34047). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Chat Software

Vendor

• danny-avila

Name

• LibreChat

Version

• 0.8.0
• 0.8.1
• 0.8.2
• 0.8.3

Website

• Product: https://github.com/danny-avila/LibreChat/

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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