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MEDIUM · 5.9

CVE-2026-54286

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...

Vulnerability 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.

CVSS Score

5.9

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE

Related Weaknesses (CWE)

CWE-22

References

FAQ

What is CVE-2026-54286?

CVE-2026-54286 is a vulnerability with a CVSS score of 5.9 (MEDIUM). 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...

How severe is CVE-2026-54286?

CVE-2026-54286 has been rated MEDIUM with a CVSS base score of 5.9/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-54286?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.