{"id":"GHSA-vwxw-jrg6-9jxv","summary":"MCP Toolbox HTTP tool path parameters allow traversal to unintended endpoints","details":"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).","aliases":["CVE-2026-11720","GO-2026-6411"],"modified":"2026-09-10T15:25:36.571215120Z","published":"2026-06-29T18:31:55Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2026-09-04T19:21:10Z","nvd_published_at":"2026-06-29T18:16:36Z","cwe_ids":["CWE-22"],"severity":"CRITICAL"},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-11720"},{"type":"WEB","url":"https://github.com/googleapis/mcp-toolbox/pull/3218"},{"type":"WEB","url":"https://github.com/googleapis/mcp-toolbox/commit/80a66021205e032a424fff87b3dc6d92da58aa77"},{"type":"PACKAGE","url":"https://github.com/googleapis/mcp-toolbox"},{"type":"WEB","url":"https://github.com/googleapis/mcp-toolbox/releases/tag/v1.3.0"}],"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":"1.3.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-vwxw-jrg6-9jxv/GHSA-vwxw-jrg6-9jxv.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"},{"type":"CVSS_V4","score":"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"}]}