CVE-2026-54286

Description

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.25, 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 admin\secret.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. This vulnerability is fixed in 4.12.25.

PUBLISHED Reserved 2026-06-12 | Published 2026-06-22 | Updated 2026-06-22 | Assigner GitHub_M

Problem types

CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Product status

References

github.com/...s/hono/security/advisories/GHSA-wwfh-h76j-fc44

cve.org (CVE-2026-54286)

nvd.nist.gov (CVE-2026-54286)

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