{"id":"CVE-2026-44428","aliases":["GHSA-95c3-6vvw-4mrq","GO-2026-5273"],"url":"https://o3.security/vulnerability/CVE-2026-44428","summary":"MCP Registry: GitHub OIDC tokens replayable across registry deployments due to shared audience","details":"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.","published":"2026-05-14T21:09:10.092Z","modified":"2026-08-07T11:48:07.325574972Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/modelcontextprotocol/registry","fixedVersion":"1.7.6"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44428.json"},{"type":"ADVISORY","url":"https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-95c3-6vvw-4mrq"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44428"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:48:07.325574972Z"}}