CVE-2026-44428

Description

The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. Prior to 1.7.6, the client-side and server-side GitHub OIDC flow is bound only to a global audience string, not to the specific registry instance being targeted. On the client side, the publisher always appends audience=mcp-registry when requesting the GitHub Actions ID token, regardless of the selected --registry URL. On the server side, the exchange endpoint validates only that same fixed audience and then derives publish permissions directly from repository_owner. As a result, a token legitimately obtained while interacting with one registry deployment remains acceptable to any other deployment that shares the same code and audience string. This vulnerability is fixed in 1.7.6.

CVSS v3.1 Score

4.7

MEDIUM

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

EPSS — Exploit Prediction

0.0001

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-918 Server-Side Request Forgery (SSRF)

Affected Products

Vendor	Product	Versions
lfprojects	mcp_registry	< 1.7.6

References

Advisories & Patches

https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-95c3-6vvw-4mrq

Frequently Asked Questions

What is CVE-2026-44428? +

The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. Prior to 1.7.6, the client-side and server-side GitHub OIDC flow is bound only to a global audience string, not to the specific registry instance being targeted. On the client side, the publisher always appends audience=mcp-registry when requesting the GitHub Actions ID token, regardless of the selected --registry URL. On the server side, the exchange endpoint validates only that same fixed audience and then derives publish permissions directly from repository_owner. As a result, a token legitimately obtained while interacting with one registry deployment remains acceptable to any other deployment that shares the same code and audience string. This vulnerability is fixed in 1.7.6. It has a CVSS v3.1 base score of 4.7 (MEDIUM).

How severe is CVE-2026-44428? +

CVE-2026-44428 has a CVSS v3.1 score of 4.7 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0001, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-44428? +

CVE-2026-44428 affects products from lfprojects, specifically: mcp_registry. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-44428? +

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.

Related Vulnerabilities

CVE-2026-41682

pupnp is an SDK for development of UPnP device and control point applications. Prior to version 1.18.5, pupnp is vulnerable …

CVE-2026-44286

FastGPT is an AI Agent building platform. Prior to version 4.14.17, an unauthenticated Server-Side Request Forgery (SSRF) vulnerability allows attackers …

CVE-2026-41172

Squidex is an open source headless content management system and content management hub. Prior to version 7.23.0, an SSRF vulnerability …

CVE-2026-41129

Craft CMS is a content management system (CMS). Versions on the 4.x branch through 4.17.8 and the 5.x branch through …

CVE-2026-5131

GREENmod uses named pipes for communication between plugins, the web portal, and the system service, but the access control lists …

CVE-2026-33975

Twenty is an open source CRM built with NestJS (Node.js). In versions 1.18.0 and earlier, the SSRF protection in twenty-server's …