CVE-2026-29045

High

Description

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to version 4.12.4, when using serveStatic together with route-based middleware protections (e.g. app.use('/admin/*', ...)), inconsistent URL decoding allowed protected static resources to be accessed without authorization. The router used decodeURI, while serveStatic used decodeURIComponent. This mismatch allowed paths containing encoded slashes (%2F) to bypass middleware protections while still resolving to the intended filesystem path. This issue has been patched in version 4.12.4.

SeverityHigh

CVSS7.5

Exploit probability—

Product

Hono

PublishedMar 4, 2026

First seenMar 4, 2026

Weakness typeCWE-177CWE-177

How to fix

Update

hono hono4.12.4 or later
hono4.12.4 or later

Affected products

Product	Affected versions	Fixed in
hono hono	v < 4.12.4	4.12.4
hononpm	v < 4.12.4	4.12.4

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