CVE Tools
Sign in

CVE-2026-39407

Hono has a middleware bypass via repeated slashes in serveStatic

Published: Apr 8, 2026Updated: Apr 21, 2026 Sources: CVE List NVDCWE-22
NVD MITRE
5.3CVSSMEDIUM
EPSS Score
0.5%
Top 63.7%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.12, a path handling inconsistency in serveStatic allows protected static files to be accessed by using repeated slashes (//) in the request path. When route-based middleware (e.g., /admin/*) is used for authorization, the router may not match paths containing repeated slashes, while serveStatic resolves them as normalized paths. This can lead to a middleware bypass. This vulnerability is fixed in 4.12.12.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:LI:NA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:LConfidentiality
Low
I:NIntegrity
None
A:NAvailability
None
Open in CVSS calculator →

Weaknesses

CWE-22

Affected Products

honohono
Library
OSS Libraries / web-framework
honohonojs
Library
OSS Libraries / web-framework
honooss-projectOSS Librariesaka hono js
honojsoss-projectOSS Librariesaka hono

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

Official Patch Available

MITRE ATT&CK

2 techniques
Collection
Discovery
View detailed technique mapping

References

https://github.com/honojs/hono/commit/9aff14bd727f8b0435c963363fd803260e7b8e3c
github.com
https://github.com/honojs/hono/releases/tag/v4.12.12
github.com
https://github.com/honojs/hono/security/advisories/GHSA-wmmm-f939-6g9c
github.com

Timeline

Published
Apr 8, 2026
Last Updated
Apr 21, 2026

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2026-39407 and every CVE in our database. Create a free account — no credit card required.

Create Free Account
Plain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows