CVE-2026-47676
Hono: app.mount() strips mount prefix using undecoded path, causing incorrect routing for percent-encoded paths
CVSS Score
5.3
EPSS Score
0.0%
EPSS Percentile
0th
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.21, app.mount() strips the mount prefix from the incoming request path using the raw URL pathname, while route matching is performed against the percent-decoded path. This inconsistency causes the prefix to be stripped at the wrong position when the path contains percent-encoded multi-byte characters, resulting in the mounted sub-application receiving an incorrect path. This vulnerability is fixed in 4.12.21.
| CWE | CWE-444 CWE-693 |
| Vendor | honojs |
| Product | hono |
| Published | May 28, 2026 |
| Last Updated | May 28, 2026 |
Stay Ahead of the Next One
Get instant alerts for honojs hono
Be the first to know when new medium vulnerabilities affecting honojs hono are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
Affected Versions
honojs / hono
< 4.12.21