CVE-2026-29045 PUBLISHED

Hono: Arbitrary file access via serveStatic vulnerability

Assigner: GitHub_M
Reserved: 03.03.2026 Published: 04.03.2026 Updated: 05.03.2026

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to version 4.12.4, when using serveStatic together with route-based middleware protections (e.g. app.use('/admin/*', ...)), inconsistent URL decoding allowed protected static resources to be accessed without authorization. The router used decodeURI, while serveStatic used decodeURIComponent. This mismatch allowed paths containing encoded slashes (%2F) to bypass middleware protections while still resolving to the intended filesystem path. This issue has been patched in version 4.12.4.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS Score: 7.5

Product Status

Vendor honojs
Product hono
Versions
  • Version < 4.12.4 is affected

References

Problem Types

  • CWE-177: Improper Handling of URL Encoding (Hex Encoding) CWE