PublicCVE

CVE-2026-27700

HIGH8.2JSON exportCreate alert

Description

Hono is a Web application framework that provides support for any JavaScript runtime. In versions 4.12.0 and 4.12.1, when using the AWS Lambda adapter (`hono/aws-lambda`) behind an Application Load Balancer (ALB), the `getConnInfo()` function incorrectly selected the first value from the `X-Forwarded-For` header. Because AWS ALB appends the real client IP address to the end of the `X-Forwarded-For` header, the first value can be attacker-controlled. This could allow IP-based access control mechanisms (such as the `ipRestriction` middleware) to be bypassed. Version 4.12.2 patches the issue.

CVSS breakdown

CVSS 3.1
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
Low
Availability
None

Affected products