Hono: JWT middleware accepts any Authorization scheme, not only Bearer

### Summary The `jwt` and `jwk` middlewares do not verify that the `Authorization` header value uses the`Bearer` 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.

Source published

4 Jun 2026 17:52:04 UTC

Source modified

10 Sep 2026 03:50:49 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Publisher rating · MODERATE