Hono: API Gateway v1 adapter can drop a distinct repeated request header value during de-duplication

Summary The AWS API Gateway v1 adapter can drop a distinct repeated request header value. When a header appears multiple times, the adapter de-duplicates values using a substring comparison instead of an exact match, so a value that is a substring of another value of the same header is omitted fo...

CVE-2026-59897

CVE-2026-59897 affects Hono: API Gateway v1 adapter (versions prior to 4.12.27). The AWS API Gateway v1 adapter drops a distinct repeated request header value due to de-duplication by substring comparison instead of exact match, which can cause incomplete data in headers like X-Forwarded-For. Thi...