{"id":"CVE-2026-6414","aliases":["EUVD-2026-23227","GHSA-x428-ghpx-8j92"],"status":"published","title":"@fastify/static vulnerable to route guard bypass via encoded path separators","description":"@fastify/static versions 8.0.0 through 9.1.0 decode percent-encoded path separators (%2F) before filesystem resolution, while Fastify's router treats them as literal characters. This mismatch allows attackers to bypass route-based middleware or guards that protect files served by @fastify/static. For example, a route guard on a protected path can be circumvented by encoding the path separator in the URL. Upgrade to @fastify/static 9.1.1 to fix this issue. There are no workarounds.","severity":{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00422,"percentile":0.36772,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-177"],"published":"2026-04-16T13:09:03Z","modified":"2026-10-28T02:31:06Z","fixes":[{"ecosystem":"npm","package":"@fastify/static","fixed_in":["9.1.1"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"@fastify/static","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"8.0.0"},{"last_affected":"9.1.0"},{"fixed":"9.1.1"}]}]},{"source":"osv","ecosystem":"npm","package":"@fastify/static","ranges":[{"type":"SEMVER","events":[{"introduced":"8.0.0"},{"fixed":"9.1.1"}]}]}],"products":[{"vendor":"@fastify/static","product":"@fastify/static"},{"vendor":"fastify","product":"fastify-static"}],"references":[{"url":"https://github.com/fastify/middie/security/advisories/GHSA-cxrg-g7r8-w69p","tags":["Not Applicable","advisory","web"]},{"url":"https://github.com/honojs/hono/security/advisories/GHSA-q5qw-h33p-qvwr","tags":["Not Applicable","advisory","web"]},{"url":"https://github.com/fastify/fastify-static/security/advisories/GHSA-x428-ghpx-8j92","tags":["Vendor Advisory","advisory","web"]},{"url":"https://cna.openjsf.org/security-advisories.html","tags":["Third Party Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-6414","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-x428-ghpx-8j92"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6414.json","tags":["advisory"]},{"url":"https://github.com/fastify/fastify-static","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-6414","title":"@fastify/static vulnerable to route guard bypass via encoded path separators","description":"@fastify/static versions 8.0.0 through 9.1.0 decode percent-encoded path separators (%2F) before filesystem resolution, while Fastify's router treats them as literal characters. This mismatch allows attackers to bypass route-based middleware or guards that protect files served by @fastify/static. For example, a route guard on a protected path can be circumvented by encoding the path separator in the URL. Upgrade to @fastify/static 9.1.1 to fix this issue. There are no workarounds.","status":"published","published":"2026-04-16T13:09:03.526Z","modified":"2026-04-16T13:48:52.393Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-177"],"updated_at":"2026-11-02T13:49:53.818886Z"}],"euvd":[{"id":"EUVD-2026-23227","description":"@fastify/static versions 8.0.0 through 9.1.0 decode percent-encoded path separators (%2F) before filesystem resolution, while Fastify's router treats them as literal characters. This mismatch allows attackers to bypass route-based middleware or guards that protect files served by @fastify/static. For example, a route guard on a protected path can be circumvented by encoding the path separator in the URL. Upgrade to @fastify/static 9.1.1 to fix this issue. There are no workarounds.","status":"published","published":"2026-04-16T13:09:03Z","modified":"2026-04-16T13:48:52Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T19:24:24.386229Z"}],"ghsa":[{"id":"GHSA-x428-ghpx-8j92","title":"@fastify/static vulnerable to route guard bypass via encoded path separators","description":"### Impact\n\n`@fastify/static` v9.1.0 and earlier decodes percent-encoded path separators (`%2F`) before filesystem resolution, but Fastify's router treats them as literal characters. This creates a routing mismatch: route guards on `/admin/*` do not match `/admin%2Fsecret.html`, but @fastify/static decodes it to `/admin/secret.html` and serves the file.\n\nApplications that rely on route-based middleware or guards to protect files served by @fastify/static can be bypassed with encoded path separators.\n\n### Patches\n\nUpgrade to `@fastify/static` \u003e= 9.1.1.\n\n### Workarounds\n\nNone. Upgrade to the patched version.","status":"published","published":"2026-04-16T22:34:03Z","modified":"2026-04-16T22:34:03Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-177"],"updated_at":"2026-11-02T14:39:55.105822Z"}],"nvd":[{"id":"CVE-2026-6414","description":"@fastify/static versions 8.0.0 through 9.1.0 decode percent-encoded path separators (%2F) before filesystem resolution, while Fastify's router treats them as literal characters. This mismatch allows attackers to bypass route-based middleware or guards that protect files served by @fastify/static. For example, a route guard on a protected path can be circumvented by encoding the path separator in the URL. Upgrade to @fastify/static 9.1.1 to fix this issue. There are no workarounds.","status":"published","published":"2026-04-16T13:16:52.243Z","modified":"2026-06-17T11:00:48.07Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-177"],"updated_at":"2026-11-02T14:12:14.748836Z"}],"osv":[{"id":"CVE-2026-6414","title":"@fastify/static vulnerable to route guard bypass via encoded path separators","description":"@fastify/static versions 8.0.0 through 9.1.0 decode percent-encoded path separators (%2F) before filesystem resolution, while Fastify's router treats them as literal characters. This mismatch allows attackers to bypass route-based middleware or guards that protect files served by @fastify/static. For example, a route guard on a protected path can be circumvented by encoding the path separator in the URL. Upgrade to @fastify/static 9.1.1 to fix this issue. There are no workarounds.","status":"published","published":"2026-04-16T13:09:03.526Z","modified":"2026-10-28T02:31:06.858952126Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-177"],"updated_at":"2026-11-02T15:45:13.752441Z"},{"id":"GHSA-x428-ghpx-8j92","title":"@fastify/static vulnerable to route guard bypass via encoded path separators","description":"### Impact\n\n`@fastify/static` v9.1.0 and earlier decodes percent-encoded path separators (`%2F`) before filesystem resolution, but Fastify's router treats them as literal characters. This creates a routing mismatch: route guards on `/admin/*` do not match `/admin%2Fsecret.html`, but @fastify/static decodes it to `/admin/secret.html` and serves the file.\n\nApplications that rely on route-based middleware or guards to protect files served by @fastify/static can be bypassed with encoded path separators.\n\n### Patches\n\nUpgrade to `@fastify/static` \u003e= 9.1.1.\n\n### Workarounds\n\nNone. Upgrade to the patched version.","status":"published","published":"2026-04-16T22:34:03Z","modified":"2026-07-08T08:14:42.025470174Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-177"],"updated_at":"2026-11-02T15:46:59.484835Z"}]}}