CVE-2026-27700

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 v3 8.2 HIGH

8.2^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 4.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/honojs/hono/commit/41adbf56e252c04611f8972364ac0887ae07a4c7	Patch
https://github.com/honojs/hono/releases/tag/v4.12.2	Product Release Notes
https://github.com/honojs/hono/security/advisories/GHSA-xh87-mx6m-69f3	Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:hono:hono:*:*:*:*:*:node.js:*:*

History

02 Mar 2026, 16:17

Type	Values Removed	Values Added
First Time		Hono hono Hono
CPE		cpe:2.3:a:hono:hono::::::node.js::*
References	~~() https://github.com/honojs/hono/commit/41adbf56e252c04611f8972364ac0887ae07a4c7 -~~	() https://github.com/honojs/hono/commit/41adbf56e252c04611f8972364ac0887ae07a4c7 - Patch
References	~~() https://github.com/honojs/hono/releases/tag/v4.12.2 -~~	() https://github.com/honojs/hono/releases/tag/v4.12.2 - Product, Release Notes
References	~~() https://github.com/honojs/hono/security/advisories/GHSA-xh87-mx6m-69f3 -~~	() https://github.com/honojs/hono/security/advisories/GHSA-xh87-mx6m-69f3 - Vendor Advisory

25 Feb 2026, 16:23

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-02-25 16:23

Updated : 2026-03-02 16:17

NVD link : CVE-2026-27700

Mitre link : CVE-2026-27700

CVE.ORG link : CVE-2026-27700

JSON object : View

Products Affected

hono

hono

CWE

CWE-290

Authentication Bypass by Spoofing

CWE-345

Insufficient Verification of Data Authenticity

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