{"id":"CVE-2026-44428","state":"PUBLISHED","title":"MCP Registry: GitHub OIDC tokens replayable across registry deployments due to shared audience","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.","publishedAt":"2026-05-14T21:09:10.092Z","updatedAt":"2026-05-15T14:22:18.973Z","severity":{"score":2.1,"label":"Low","version":"4.0","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","source":"GitHub_M"},"assigner":"GitHub_M","products":["modelcontextprotocol registry"],"affected":[{"vendor":"modelcontextprotocol","product":"registry","versions":[{"version":"< 1.7.6","status":"affected"}]}],"references":["https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-95c3-6vvw-4mrq"],"weaknesses":["CWE-918"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/44xxx/CVE-2026-44428.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-44428","state":"PUBLISHED","datePublished":"2026-05-14T21:09:10.092Z","dateUpdated":"2026-05-15T14:22:18.973Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-05-06T14:40:00.953Z"},"containers":{"cna":{"title":"MCP Registry: GitHub OIDC tokens replayable across registry deployments due to shared audience","descriptions":[{"lang":"en","value":"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":[{"vendor":"modelcontextprotocol","product":"registry","versions":[{"version":"< 1.7.6","status":"affected"}]}],"references":[{"url":"https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-95c3-6vvw-4mrq","name":"https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-95c3-6vvw-4mrq","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"ACTIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"LOW","subAvailabilityImpact":"NONE","baseScore":2.1,"baseSeverity":"LOW","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-918","lang":"en","description":"CWE-918: Server-Side Request Forgery (SSRF)","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-05-14T21:09:10.092Z"},"source":{"advisory":"GHSA-95c3-6vvw-4mrq","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-15T14:22:02.074993Z","id":"CVE-2026-44428","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-15T14:22:18.973Z"}}]}}}