PT-2026-49733 · Npm · Hono

Publicado

2026-06-16

·

Atualizado

2026-06-16

·

CVE-2026-54286

CVSS v3.1

5.9

Média

VetorAV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Summary

On Windows hosts, an encoded backslash (%5C) in the request path decodes to ``, which the Windows path resolver treats as a separator. serve-static then resolves a single URL segment such as adminsecret.txt into a nested file under the root and serves it, letting an attacker read static files meant to be protected behind prefix-mounted middleware. Directory escape (..) remains blocked.

Details

The router splits paths only on /, so /admin%5Csecret.txt is one segment and middleware on /admin/* does not run. The serve-static guard rejects ./.. and consecutive separators but lets a lone `` through; on Windows the file resolver re-splits it into the protected subtree.
This affects Windows hosts serving static files via the Node, Bun, or Deno adapters that guard a static subtree with prefix-mounted middleware.

Impact

An unauthenticated attacker can read static files under a middleware-guarded prefix on Windows hosts. The read stays within the configured root; escape outside the root is not possible.

Correção

Path traversal

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Enumeração de Fraquezas

Identificadores relacionados

CVE-2026-54286
GHSA-WWFH-H76J-FC44

Produtos afetados

Hono