{"id":"GHSA-vwxw-jrg6-9jxv","revision":"04a89a7e2c6b4bf88257cbbb3a74ba09","records":[{"revision":"04a89a7e2c6b4bf88257cbbb3a74ba09","observedAt":"2026-10-24T13:19:41.952+00:00","statement":{"source":"osv","id":"GHSA-vwxw-jrg6-9jxv","aliases":["CVE-2026-11720","GO-2026-6411"],"title":"MCP Toolbox HTTP tool path parameters allow traversal to unintended endpoints","description":"A path traversal vulnerability exists in the HTTP tool URL builder of googleapis/mcp-toolbox.\n\nWhen constructing downstream API requests, the URL builder substitutes user-controlled pathParams into the configured tool path and parses the resulting string as a relative URL. While it checks that the input does not alter the scheme, host, or user info, it relies on ResolveReference for the final URL resolution. Because dot segments (../) are normalized during this resolution step, an attacker can supply path parameters containing directory traversal sequences to escape the operator-configured path scope. This allows the client to coerce the toolbox into making requests to unintended endpoints on the same target host while forwarding the toolbox's configured credentials (e.g., bypassing a restricted path like /api/v1/users/{{.id}} to reach /admin/secrets).","state":0,"publishedAt":"2026-06-29T18:31:55+00:00","modifiedAt":"2026-09-10T15:25:39.1872802+00:00","affected":[{"ecosystem":"Go","name":"github.com/googleapis/mcp-toolbox","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"1.3.0"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","score":null,"severity":null},{"system":"CVSS_V4","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"CRITICAL"}],"references":["https://nvd.nist.gov/vuln/detail/CVE-2026-11720","https://github.com/googleapis/mcp-toolbox/pull/3218","https://github.com/googleapis/mcp-toolbox/commit/80a66021205e032a424fff87b3dc6d92da58aa77","https://github.com/googleapis/mcp-toolbox","https://github.com/googleapis/mcp-toolbox/releases/tag/v1.3.0"],"sourceUrl":"https://github.com/advisories/GHSA-vwxw-jrg6-9jxv","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-vwxw-jrg6-9jxv","identifiers":["GHSA-vwxw-jrg6-9jxv","CVE-2026-11720","GO-2026-6411"]},"retained":false,"historicalAffected":[]}],"coverage":[]}