{"id":"EUVD-2026-32672","revision":"18552fcfb07e43d38c80f20730e2cd6c","records":[{"revision":"18552fcfb07e43d38c80f20730e2cd6c","observedAt":"2026-10-30T12:56:09.601+00:00","statement":{"source":"euvd","id":"EUVD-2026-32672","aliases":["CVE-2026-9739","GHSA-7pf3-8xx7-rvhf"],"title":"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-O…","description":"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.","state":0,"publishedAt":null,"modifiedAt":null,"affected":[],"metrics":[{"system":"EUVD CVSS 4.0","vector":"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","score":9.4,"severity":null}],"references":["https://github.com/googleapis/mcp-toolbox/issues/3053","https://github.com/googleapis/mcp-toolbox/pull/3054"],"sourceUrl":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-32672","license":"ENISA EUVD · source terms and attribution apply","enrichment":{"sourceStatus":null,"weaknesses":[],"productCriteria":[],"sourceDates":{"datePublished":"May 27, 2026, 9:38:55 PM","dateUpdated":"May 28, 2026, 1:20:43 PM"},"relatedAdvisories":[],"note":"EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON."},"key":"euvd:EUVD-2026-32672","identifiers":["EUVD-2026-32672","CVE-2026-9739","GHSA-7pf3-8xx7-rvhf"]},"retained":false,"historicalAffected":[]}],"coverage":[]}