CVE-2026-47673

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.

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.

Summary

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.

Details

When processing an Authorization (or custom) header, the middleware splits the value on whitespace and uses the second token as the JWT to verify. It does not check that the first token is bearer (case-insensitively). RFC 6750 specifies that JWT bearer tokens must be presented using the Bearer scheme; other scheme identifiers carry distinct semantics and may be subject to different policies in network-layer security controls.

This discrepancy means that scheme-aware external controls — such as WAF rules, API gateways, or reverse proxies that apply policies specific to the Bearer scheme identifier — can be bypassed by presenting a valid JWT under a different scheme name.

This issue affects hono/jwt and hono/jwk middleware.

Impact

An attacker who possesses a valid JWT may present it under a non-Bearer scheme identifier and still pass middleware authentication.

This may lead to:

• Bypass of network-layer security controls that inspect or filter requests based on the authorization scheme identifier
• Token reuse across authentication schemes in applications that use multiple authorization mechanisms

This issue affects applications where hono/jwt or hono/jwk authentication is combined with external controls that enforce scheme-based access policies.

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.

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.

Summary

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.

Details

When processing an Authorization (or custom) header, the middleware splits the value on whitespace and uses the second token as the JWT to verify. It does not check that the first token is bearer (case-insensitively). RFC 6750 specifies that JWT bearer tokens must be presented using the Bearer scheme; other scheme identifiers carry distinct semantics and may be subject to different policies in network-layer security controls.

This discrepancy means that scheme-aware external controls — such as WAF rules, API gateways, or reverse proxies that apply policies specific to the Bearer scheme identifier — can be bypassed by presenting a valid JWT under a different scheme name.

This issue affects hono/jwt and hono/jwk middleware.

Impact

An attacker who possesses a valid JWT may present it under a non-Bearer scheme identifier and still pass middleware authentication.

This may lead to:

• Bypass of network-layer security controls that inspect or filter requests based on the authorization scheme identifier
• Token reuse across authentication schemes in applications that use multiple authorization mechanisms

This issue affects applications where hono/jwt or hono/jwk authentication is combined with external controls that enforce scheme-based access policies.

TuxCare rebuilt hono to address 15 CVEs. Fixed in 3.12.12-tuxcare.1.

Root has patched CVE-2026-47673 in the @rootio/hono package for Root:npm. Multiple fixed versions available.