GHSA-WC8C-QW6V-H7F6

Vulnerability from github – Published: 2026-03-04 20:05 – Updated: 2026-03-06 22:43
VLAI?
Summary
@hono/node-server has authorization bypass for protected static paths via encoded slashes in Serve Static Middleware
Details

Summary

When using @hono/node-server's static file serving together with route-based middleware protections (e.g. protecting /admin/*), inconsistent URL decoding can allow protected static resources to be accessed without authorization.

In particular, paths containing encoded slashes (%2F) may be evaluated differently by routing/middleware matching versus static file path resolution, enabling a bypass where middleware does not run but the static file is still served.

Details

The routing layer and the node-server static handler normalize request paths differently. The router preserves %2F as a literal string when matching routes, while the static handler decodes %2F into / before resolving the filesystem path.

Example request:

  • /admin%2Fsecret.html

This may: - fail to match middleware intended for /admin/*, but - still be resolved by the static handler as /admin/secret.html under the configured static root.

This does not allow access outside the configured static root and is not a path traversal vulnerability.

Impact

An unauthenticated attacker could bypass route-based authorization protections for protected static resources by supplying paths containing encoded slashes.

Applications relying solely on route-based middleware to protect static subpaths under the same static root may have exposed those resources.

Severity ?
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Show details on source website
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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@hono/node-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.19.10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-29087"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-863"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-04T20:05:49Z",
    "nvd_published_at": "2026-03-06T18:16:19Z",
    "severity": "HIGH"
  },
  "details": "## Summary\n\nWhen using @hono/node-server\u0027s static file serving together with route-based middleware protections (e.g. protecting `/admin/*`), inconsistent URL decoding can allow protected static resources to be accessed without authorization.\n\nIn particular, paths containing encoded slashes (`%2F`) may be evaluated differently by routing/middleware matching versus static file path resolution, enabling a bypass where middleware does not run but the static file is still served.\n\n## Details\n\nThe routing layer and the node-server static handler normalize request paths differently. The router preserves `%2F` as a literal string when matching routes, while the static handler decodes `%2F` into `/` before resolving the filesystem path.\n\nExample request:\n\n- `/admin%2Fsecret.html`\n\nThis may:\n- fail to match middleware intended for `/admin/*`, but\n- still be resolved by the static handler as `/admin/secret.html` under the configured static root.\n\nThis does not allow access outside the configured static root and is not a path traversal vulnerability.\n\n## Impact\n\nAn unauthenticated attacker could bypass route-based authorization protections for protected static resources by supplying paths containing encoded slashes.\n\nApplications relying solely on route-based middleware to protect static subpaths under the same static root may have exposed those resources.",
  "id": "GHSA-wc8c-qw6v-h7f6",
  "modified": "2026-03-06T22:43:58Z",
  "published": "2026-03-04T20:05:49Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/honojs/node-server/security/advisories/GHSA-wc8c-qw6v-h7f6"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-29087"
    },
    {
      "type": "WEB",
      "url": "https://github.com/honojs/node-server/commit/455015be1697dd89974a68b70350ea7b2d126d2e"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/honojs/node-server"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "@hono/node-server has authorization bypass for protected static paths via encoded slashes in Serve Static Middleware"
}


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