# CVE-2026-47673: Hono: JWT middleware accepts any Authorization scheme, not only Bearer


- **Severity:** Medium 4.8 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 28 May 2026
- **Updated:** 30 May 2026
- **Also known as:** ECHO-37b1-b06d-808f, GHSA-f577-qrjj-4474, MINI-2ccx-wj8f-4f8f, MINI-2v7h-hpfm-qg4r, MINI-7q9f-9qj4-98cr, MINI-99j4-jjv5-6jvp, MINI-c3q7-xw6f-p7m5, MINI-c496-2w45-r534, MINI-ffh5-prm2-6jp5, MINI-h4jf-gq5m-88j4, MINI-h9f3-7fpc-7cmj, MINI-qfhj-36ph-qppx, MINI-xq33-8fpr-69gj, ROOT-APP-NPM-CVE-2026-47673

## What is CVE-2026-47673?

CVE-2026-47673 is a medium-severity vulnerability in honojs hono, published on 28 May 2026. 

### Official description

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.

Weakness: CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2026-47673?

2 open source packages ship an affected version, including hono. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `hono` | npm | All versions | 4.12.21 |
| `hono` | npm | All versions | 4.12.21 |

Products: Hono Hono.

## How do I fix CVE-2026-47673?

Upgrade hono to 4.12.21 or later.

## Is CVE-2026-47673 being exploited?

There is no known exploitation of CVE-2026-47673 in the wild and no public exploit code.

## Other vulnerabilities in honojs hono

- [CVE-2026-27700](https://insights.sbomify.com/CVE-2026-27700/): Hono is Vulnerable to Authentication Bypass by IP Spoofing in AWS Lambda ALB conninfo (high 8.2)
- [CVE-2026-22817](https://insights.sbomify.com/CVE-2026-22817/): JWT Algorithm Confusion via Unsafe Default (HS256) in Hono JWT Middleware Allows Token Forgery and Auth Bypass (high 8.2)
- [CVE-2026-22818](https://insights.sbomify.com/CVE-2026-22818/): JWT algorithm confusion in Hono JWK Auth Middleware when JWK lacks "alg" (untrusted header.alg fallback) (high 8.2)
- [CVE-2025-62610](https://insights.sbomify.com/CVE-2025-62610/): Hono Improperly Authorizes JWT Audience Validation (high 8.1)
- [CVE-2026-29045](https://insights.sbomify.com/CVE-2026-29045/): Hono: Arbitrary file access via serveStatic vulnerability (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-47673 and fix it if it is affected.

What it is: CVE-2026-47673 is a medium-severity vulnerability in honojs hono, published on 28 May 2026. 
Exploitation: There is no known exploitation of CVE-2026-47673 in the wild and no public exploit code.

Affected packages and fixed versions:
- hono (npm): affected all versions; fixed in 4.12.21
- hono (npm): affected all versions; fixed in 4.12.21

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-47673/ (Markdown: https://insights.sbomify.com/CVE-2026-47673/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-47673
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-47673
- OSV: https://osv.dev/vulnerability/CVE-2026-47673

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-47673/
Summaries are generated and may contain mistakes; the official description above is the record.