VulnerabilityAnalyzed

CVE-2026-47676

This vulnerability is fixed in 4.12.21.

MEDIUM 5.3EPSS 0.26%

Does this matter?

Lower severity and a low EPSS score (0.26%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 3.1: 5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS: 0.26% probability · 18th percentile
CISA KEV: Not listed
Weakness: CWE-444, CWE-693
Affected: hono/hono
Source: security-advisories@github.com

References

https://github.com/honojs/hono/security/advisories/GHSA-2gcr-mfcq-wcc3Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.