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OpenAdvisories
High · 8.2 CVE-2026-27700 EUVD-2026-8644GHSA-xh87-mx6m-69f3

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

Published Feb 25, 2026 · Updated Feb 27, 2026 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
honojs hono >= 4.12.0, < 4.12.2 —

Affected packages

EcosystemPackageAffectedFixedRecord
npm hono >= 4.12.0, < 4.12.2 4.12.2 GHSA-xh87-mx6m-69f3

References