CVE-2026-54288 PUBLISHED

Hono: Body Limit Middleware can be bypassed on AWS Lambda by understating `Content-Length`

Assigner: GitHub_M
Reserved: 12.06.2026 Published: 22.06.2026 Updated: 23.06.2026

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.25, the Body Limit Middleware trusts the request's Content-Length header to decide whether a body is within the limit. On AWS Lambda (API Gateway v1/v2, ALB, VPC Lattice, and Lambda@Edge) the body is delivered fully buffered and the adapter builds the request with the client-declared Content-Length, which need not match the actual payload. A client can declare a tiny Content-Length while sending a much larger body, slipping past the limit. This vulnerability is fixed in 4.12.25.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
CVSS Score: 6.5

Product Status

Vendor honojs
Product hono
Versions
  • Version < 4.12.25 is affected

References

Problem Types

  • CWE-345: Insufficient Verification of Data Authenticity CWE