Protected-file disclosure via repeated-slash middleware bypass
Published Apr 8, 2026 · Updated Apr 8, 2026
Path traversal in Hono @hono/node-server before 1.19.13 allows remote attackers to read protected static files via repeated URL slashes. The router leaves repeated slashes unmatched by route-based authorization middleware, while serveStatic normalizes the same path and serves the resolved file. Exposure requires an application to protect files with route-based middleware and serveStatic; the consequence is unauthorized read access under the static root.
Summary
What happened
Path traversal in Hono @hono/node-server before 1.19.13 allows remote attackers to read protected static files via repeated URL slashes. The router leaves repeated slashes unmatched by route-based authorization middleware, while serveStatic normalizes the same path and serves the resolved file. Exposure requires an application to protect files with route-based middleware and serveStatic; the consequence is unauthorized read access under the static root.
The record
- CVE
- CVE-2026-39406
- Published
- Apr 8, 2026
- Updated
- Apr 8, 2026
- Vendor
- Hono
- Product
- @hono/node-server
- Classifications
- CWE-22, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 8, 2026CVE publishedPublication date reported by the CVE source.
- Apr 8, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 1.19.13
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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