CVE-2026-54288

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

Published Jun 22, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-rv63-4mwf-qqc2 hono: Body Limit Middleware can be bypassed on AWS Lambda by understating `Content-Length`
History
Type Values Removed Values Added
First Time appeared Hono
Hono hono
Vendors & Products Hono
Hono hono
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title Hono: Body Limit Middleware can be bypassed on AWS Lambda by understating `Content-Length`
Weaknesses CWE-345
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jun 23, 2026, 4:11 PM
Reserved
Jun 12, 2026, 5:46 PM
Status
Deferred
Published
Jun 22, 2026, 7:17 PM
Modified
Oct 25, 2026, 11:10 PM