Authorization Weakness in Hono Web Application Framework
CVE-2026-29045

7.5HIGH

Key Information:

Vendor

Honojs

Status
Hono
Vendor
CVE Published:
4 March 2026

What is CVE-2026-29045?

The Hono Web Application Framework, which supports various JavaScript runtimes, exhibited an authorization bypass issue prior to version 4.12.4. An inconsistency in URL decoding methods between the routing and static file serving components allowed attackers to access protected resources without proper authorization. Specifically, the routing mechanism leveraged decodeURI, while the static serving function utilized decodeURIComponent. This mismatch enabled attackers to exploit encoded slashes (%2F) in URLs, thus circumventing middleware protections and accessing restricted filesystem paths. This vulnerability has been addressed in the patched version 4.12.4.

Affected Version(s)

hono < 4.12.4

References

https://github.com/honojs/hono/security/advisories/GHSA-q...
x_refsource_CONFIRM
https://github.com/honojs/hono/commit/6a0607a929d888893f0...
x_refsource_MISC

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.