CVE-2026-54286 Details
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.
A path traversal vulnerability has been identified in the Hono web application framework, prior to version 4.12.25, on Windows hosts. The issue arises when an encoded backslash (%5C) in the request path is decoded to a backslash, which the Windows path resolver interprets as a separator. This allows the 'serve-static' middleware to resolve a single URL segment, such as 'admin\secret.txt', into a nested file under the root directory. Consequently, an attacker could read static files that are meant to be protected by prefix-mounted middleware. This vulnerability affects Windows hosts serving static files through the Node, Bun, or Deno adapters, with middleware guarding a static subtree.
Users can upgrade to Hono version 4.12.25 or later to address this vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jun 22, 2026CISA-ADP
Assessed Jun 23, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/honojs/hono/security/advisories/GHSA-wwfh-h76j-fc44 | [email protected] | AdvisoryRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-22 | Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Hono | < 4.12.25 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 23, 2026 | CVE Modified | CISA-ADP |
| Jun 22, 2026 | New CVE Received | [email protected] |