CVE-2026-54030

Description

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.

CVSS v3.1 Score

8.0

HIGH

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N

EPSS — Exploit Prediction

0.0011

Probability of exploitation

0.02%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-346 CWE-346

Affected Products

Vendor	Product	Versions
librechat	librechat	< 0.8.4
librechat	librechat	All

References

Advisories & Patches

https://github.com/danny-avila/LibreChat/security/advisories/GHSA-gvpj-vm2f-2m23 https://github.com/danny-avila/LibreChat/security/advisories/GHSA-gvpj-vm2f-2m23

Exploits

https://github.com/danny-avila/LibreChat/security/advisories/GHSA-gvpj-vm2f-2m23 https://github.com/danny-avila/LibreChat/security/advisories/GHSA-gvpj-vm2f-2m23

Frequently Asked Questions

What is CVE-2026-54030? +

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. It has a CVSS v3.1 base score of 8.0 (HIGH).

How severe is CVE-2026-54030? +

CVE-2026-54030 has a CVSS v3.1 score of 8.0 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0011, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-54030? +

CVE-2026-54030 affects products from librechat, specifically: librechat. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-54030? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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