CVE-2026-109955

Hono 4.12.4 before 4.13.11 Middleware Bypass via serveStatic Double Decoding

State: Published
Severity: 6.9 Medium
Published: Oct 13, 2026
Updated: Oct 13, 2026
Reserved: Oct 13, 2026

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.

Scores

CVSS	Score	Vector	Source
4.0	6.9 Medium	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N	VulnCheck
3.1	5.3 Medium	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N	VulnCheck

Weaknesses

CWE-174 Double Decoding of the Same Data

Affected Products

Product	Versions
honohonojs	4.12.4 to before 4.13.11Affected 4.13.11Not affected

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 Decodingthird-party-advisory

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