CVE-2026-27700CWE-290CWE-345

Hono is Vulnerable to Authentication Bypass by IP Spoofing in AWS Lambda ALB conninfo

High · published February 25, 2026

CVSS v3.1
8.2
EPSS
0%
Percentile
27.4
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.2 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00350 · 27.4th percentile
Weaknesses
CWE-290 · Authentication Bypass by Spoofing; CWE-345 · Insufficient Verification of Data Authenticity
Published
2026-02-25T15:01Z
EPSS history
Timeline
  • 25 FEB 15:01Z
    Hono is Vulnerable to Authentication Bypass by IP Spoofing in AWS Lambda ALB conninfo
    cvelistv5