PT-2026-56507 · Honojs · Hono

Published 2026-07-08 · Updated 2026-07-08 · CVE-2026-59897

NVD

CVSS v3.1

4.8

Medium

Base vector

AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

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.

Fix

Weakness Enumeration

CWE-348

Related Identifiers

CVE-2026-59897

Affected Products

Hono

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-59897 · Security Note
• https://github.com/honojs/hono/releases/tag/v4.12.27 · Note
• https://github.com/honojs/hono/security/advisories/GHSA-xgm2-5f3f-mvvc · Note
• https://github.com/honojs/hono/commit/aa921770d09bc35970362d5a2630a878f6d982fd · Note