{"id":"GHSA-7pf3-8xx7-rvhf","summary":"MCP Toolbox for Databases vulnerable to DNS rebinding attacks","details":"Vulnerable to DNS rebinding attacks when using SSE (http://b/499408790). During the beta phase, we implemented `allowed-origins` and `allowed-hosts` flags to align with MCP security guidelines. However, the hardcoded `Access-Control-Allow-Origin: *` header in the SSE initialization handler was inadvertently retained. This vulnerability specifically impacts users connecting via Toolbox using SSE under specification v2024-11-05.","aliases":["CVE-2026-9739","GO-2026-5870"],"modified":"2026-07-07T16:11:35.449476804Z","published":"2026-05-28T00:30:29Z","database_specific":{"cwe_ids":["CWE-942"],"severity":"CRITICAL","github_reviewed":true,"github_reviewed_at":"2026-07-01T20:54:22Z","nvd_published_at":"2026-05-27T23:16:48Z"},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-9739"},{"type":"WEB","url":"https://github.com/googleapis/mcp-toolbox/issues/3053"},{"type":"WEB","url":"https://github.com/googleapis/mcp-toolbox/pull/3054"},{"type":"WEB","url":"https://github.com/googleapis/mcp-toolbox/commit/c4c7bd917e686de68e2be866cfe3872c3439efae"},{"type":"PACKAGE","url":"https://github.com/googleapis/mcp-toolbox"}],"affected":[{"package":{"name":"github.com/googleapis/mcp-toolbox","ecosystem":"Go","purl":"pkg:golang/github.com/googleapis/mcp-toolbox"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.2.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-7pf3-8xx7-rvhf/GHSA-7pf3-8xx7-rvhf.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H"}]}