{"id":"CVE-2026-39406","aliases":["GHSA-92pp-h63x-v22m"],"url":"https://o3.security/vulnerability/CVE-2026-39406","summary":"@hono/node-server has a middleware bypass via repeated slashes in serveStatic","details":"## Summary\n\nA path handling inconsistency in `serveStatic` allows protected static files to be accessed by using repeated slashes (`//`) in the request path.\n\nWhen route-based middleware (e.g., `/admin/*`) is used for authorization, the router may not match paths containing repeated slashes, while `serveStatic` resolves them as normalized paths. This can lead to a middleware bypass.\n\n## Details\n\nThe routing layer and `serveStatic` handle repeated slashes differently.\n\nFor example:\n\n- `/admin/secret.txt` => matches `/admin/*`\n- `//admin/secret.txt` => may not match `/admin/*`\n\nThis inconsistency allows a request such as:\n\n```\nGET //admin/secret.txt\n```\n\nto bypass middleware registered on `/admin/*` and access protected files.\n\n## Impact\n\nAn attacker can access static files that are intended to be protected by route-based middleware by using repeated slashes in the request path.\n\nThis can lead to unauthorized access to sensitive files under the static root.\n\nThis issue affects applications that rely on `serveStatic` together with route-based middleware for access control.","published":"2026-04-08T14:34:30.543Z","modified":"2026-08-12T03:51:19.721826987Z","cvss":{"score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"@hono/node-server","fixedVersion":"1.19.13"}],"fix":{"url":"https://github.com/honojs/node-server/commit/025c30f55d589ddbe6048b151d77e904f67a8cc2","label":"honojs/node-server@025c30f"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39406.json"},{"type":"ADVISORY","url":"https://github.com/honojs/node-server/security/advisories/GHSA-92pp-h63x-v22m"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-39406"},{"type":"WEB","url":"https://github.com/honojs/node-server/commit/025c30f55d589ddbe6048b151d77e904f67a8cc2"},{"type":"PACKAGE","url":"https://github.com/honojs/node-server"},{"type":"WEB","url":"https://github.com/honojs/node-server/releases/tag/v1.19.13"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:19.721826987Z"}}