Medium severity · published Oct 13, 2026
CVE-2026-109955
Hono 4.12.4 before 4.13.11 Middleware Bypass via serveStatic Double Decoding
5.3
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 24% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
HO
hono · honojs
4.12.4 before 4.13.11 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-109955
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-109955
vendor-advisory
https://github.com/honojs/hono/security/advisories/GHSA-5r4p-p66f-jhc7
third-party-advisory
https://www.vulncheck.com/advisories/hono-4.12.4-before-4.13.11-middleware-bypass-via-servestatic-double-decoding
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