honojs hono up to 4.12.20 improper authorization

Summaryinfo

A vulnerability marked as critical has been reported in honojs hono up to 4.12.20. Impacted is an unknown function. This manipulation causes improper authorization. This vulnerability is handled as CVE-2026-47673. The attack can be initiated remotely. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in honojs hono up to 4.12.20. It has been declared as critical. Affected by this vulnerability is an unknown code. The manipulation with an unknown input leads to a improper authorization vulnerability. The CWE definition for the vulnerability is CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.21, the jwt and jwk middlewares do not verify that the Authorization header value uses theBearer scheme. Any two-part header value — regardless of the scheme name in the first position — proceeds to JWT verification. A request presenting a valid JWT under a non-Bearer scheme identifier (such as Basic or Token) is authenticated identically to a correctly formed Bearer request. This vulnerability is fixed in 4.12.21.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-47673 since 05/19/2026. The exploitation appears to be difficult. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1548.002 according to MITRE ATT&CK.

Upgrading to version 4.12.21 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-32927). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

• honojs

Name

• hono

Version

• 4.12.0
• 4.12.1
• 4.12.2
• 4.12.3
• 4.12.4
• 4.12.5
• 4.12.6
• 4.12.7
• 4.12.8
• 4.12.9
• 4.12.10
• 4.12.11
• 4.12.12
• 4.12.13
• 4.12.14
• 4.12.15
• 4.12.16
• 4.12.17
• 4.12.18
• 4.12.19
• 4.12.20

Website

• Product: https://github.com/honojs/hono/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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