Vulnerability · Published Oct 13, 2026 · Assigned by VulnCheck

CVE-2026-109955Hono 4.12.4 before 4.13.11 Middleware Bypass via serveStatic Double Decoding

Medium 5.3

In plain English

A medium-severity security flaw in hono from honojs. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)0.3%top 75.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Hono from 4.12.4 before 4.13.11 contains a middleware bypass vulnerability in serveStatic that allows unauthenticated attackers to skip prefix middleware by exploiting double path decoding. Attackers can send malformed percent-encoded paths that the router matches in encoded form, reaching static files without authentication checks running.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	hono	4.13.11	GHSA-5r4p-p66f-jhc7

Affected products (as reported)

Vendor	Product	Versions
honojs	hono	4.12.4 – before 4.13.11

Weakness: CWE-174 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

References

GitHub Security Advisory (GHSA-5r4p-p66f-jhc7) vendor-advisory
VulnCheck Advisory: Hono 4.12.4 before 4.13.11 Middleware Bypass via serveStatic Double Decoding third-party-advisory