Hono: API Gateway v1 adapter can drop a distinct repeated request header value during de-duplication
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- Partial Red Hat: 4 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA, GitHub and Red Hat.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| honojs | hono | 4.3.3 to before 4.12.27 | 4.12.27 | Patch available | CNA |
| — | hono (npm) | 4.3.3 to before 4.12.27 | 4.12.27 | Patch available | GHSA-xgm2-5f3f-mvvc |
- hono Vendorhonojs Affected 4.3.3 to before 4.12.27 Fixed in 4.12.27 Patch available CNA
- hono (npm) Vendor— Affected 4.3.3 to before 4.12.27 Fixed in 4.12.27 Patch available GHSA-xgm2-5f3f-mvvc
Remediation
- Fix · CNA hono (honojs) Fixed in 4.12.27
- Fix · GHSA-xgm2-5f3f-mvvc hono (npm) Fixed in 4.12.27 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Migration Toolkit for Applications 8 | Affected | No fix yet: Fix deferred |
| Red Hat Ansible Automation Platform 2 | Affected | No fix yet: Fix deferred |
| Red Hat Developer Hub 1 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Dev Spaces | Affected | No fix yet: Fix deferred |
Not affected: 1 product
- Red Hat Hardened Images
Timeline
- 2026-10-02 Threatist record created from CVE-2026-59897
- 2026-10-03 Alias added: GHSA-xgm2-5f3f-mvvc
- 2026-10-27 Affected versions changed · Red Hat
References
Advisory 2
More honojs Hono vulnerabilities
- TI-2024-21741 Hono vulnerable to Restricted Directory Traversal in serveStatic with deno CVSS 3.1MEDIUM 5.3
- TI-2024-32610 Hono vulnerable to bypass of CSRF Middleware by a request without Content-Type header. CVSS 3.1MEDIUM 5.9
- TI-2024-29381 Hono CSRF middleware can be bypassed using crafted Content-Type header CVSS 3.1MEDIUM 5.0
- TI-2026-23190 Hono: Arbitrary file access via serveStatic vulnerability CVSS 3.1CRITICAL 9.8
- TI-2026-22076 Hono is Vulnerable to Authentication Bypass by IP Spoofing in AWS Lambda ALB conninfo CVSS 3.1HIGH 8.2
- TI-2026-18334 JWT algorithm confusion in Hono JWK Auth Middleware when JWK lacks "alg" (untrusted header.alg fallback) CVSS 3.1HIGH 8.2
Sources
- CVE-2026-59897 · CVE Program
- CVE-2026-59897 · NVD
- FIRST EPSS
- GHSA-xgm2-5f3f-mvvc · GitHub Advisory Database · CC BY 4.0
- CVE-2026-59897 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences