{"id":"CVE-2026-9739","aliases":["GO-2026-5870"],"url":"https://o3.security/vulnerability/CVE-2026-9739","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.","published":"2026-05-28T00:30:29Z","modified":"2026-07-07T16:11:35.449476804Z","cvss":null,"epss":{"score":0.00279,"percentile":0.1984,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/googleapis/mcp-toolbox","fixedVersion":"1.2.0"}],"fix":{"url":"https://github.com/googleapis/mcp-toolbox/pull/3054","label":"googleapis/mcp-toolbox#3054"},"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"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-07T16:11:35.449476804Z"}}