medium4.8
CVE-2026-59897
Hono: API Gateway v1 adapter can drop a distinct repeated request header value during de-duplication
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | hono | >= 4.3.3, < 4.12.27 | 4.12.27 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Hono | Hono | from 4.3.3 before 4.12.27 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-xgm2-5f3f-mvvc
- https://github.com/honojs/hono/security/advisories/GHSA-xgm2-5f3f-mvvc
- https://nvd.nist.gov/vuln/detail/CVE-2026-59897
- https://github.com/honojs/hono/commit/aa921770d09bc35970362d5a2630a878f6d982fd
- https://github.com/honojs/hono/releases/tag/v4.12.27