CVE-2026-59897
Medium
Description
Hono is a Web application framework that provides support for any JavaScript runtime. From 4.3.3 before 4.12.27, the AWS API Gateway v1 adapter can drop a distinct repeated request header value because it de-duplicates values using a substring comparison instead of an exact match, so middleware or application logic that depends on the complete X-Forwarded-For chain, rate limiting, audit logging, or proxy-chain validation can receive incomplete data. This issue is fixed in version 4.12.27.
SeverityMedium
CVSS4.8
Exploit probability—
Product
Hono
PublishedJul 8, 2026
First seenJul 8, 2026
Weakness typeCWE-348CWE-348
How to fix
Update
- hono hono4.12.27 or later
- hono4.12.27 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| hono hono | 4.3.3 ≤ v < 4.12.27 | 4.12.27 |
| hononpm | 4.3.3 ≤ v < 4.12.27 | 4.12.27 |
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