CVE-2026-27700 – Hono is Vulnerable to Authentication Bypass by IP Spoofing in AWS Lambda ALB conninfo

CVE ID : CVE-2026-27700

Published : Feb. 25, 2026, 4:23 p.m. | 45 minutes ago

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.

Severity: 8.2 | HIGH

Visit the link for more details, such as CVSS details, affected products, timeline, and more…