Vulnerability · Published May 14, 2026 · Assigned by GitHub_M
CVE-2026-44428MCP Registry: GitHub OIDC tokens replayable across registry deployments due to shared audience
Low 2.1
In plain English
A low-severity server-side request forgery in registry from modelcontextprotocol. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/modelcontextprotocol/registry | 1.7.6 | GHSA-95c3-6vvw-4mrq |
| Go | github.com/modelcontextprotocol/registry | 1.7.6 | GO-2026-5273 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| modelcontextprotocol | registry | < 1.7.6 |
Weakness: CWE-918 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N