CVE-2026-59897CWE-348

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

Medium · published July 8, 2026

CVSS v3.1
4.8
EPSS
0%
Percentile
7.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
4.8 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00180 · 7.1th percentile
Weakness
CWE-348 · Use of Less Trusted Source
Published
2026-07-08T16:06Z
EPSS history
Timeline
  • 08 JUL 16:06Z
    Hono: API Gateway v1 adapter can drop a distinct repeated request header value during de-duplication
    cvelistv5